Parallels Virtuozzo Containers - 4.7 - Linux User's Guide

Parallels Virtuozzo Containers 4.7 for Linux

User's Guide

Parallels IP Holdings GmbH. c/o Parallels International GmbH. Parallels International GmbH Vordergasse 49 CH8200 Schaffhausen Switzerland Tel: + 41 526320 411 Fax: + 41 52672 2010 www.parallels.com

This product is protected by United States and international copyright laws. The product’s underlying technology, patents, and trademarks are listed at http://www.parallels.com/trademarks.

Microsoft, Windows, Windows Server, Windows NT, Windows Vista, and MS-DOS are registered trademarks of Microsoft Corporation. Apple, Mac, the Mac logo, Mac OS, iPad, iPhone, iPod touch, FaceTime HD camera and iSight are trademarks of Apple Inc., registered in the US and other countries. Linux is a registered trademark of Linus Torvalds. All other marks and names mentioned herein may be trademarks of their respective owners.

Contents

Introduction ............................................................................................................. 11

About This Guide .......................................................................................................... 11

Organization of This Guide .................................................................................................... 12

Documentation Conventions ................................................................................................. 13

Getting Help .................................................................................................................. 14

Feedback ...................................................................................................................... 14

Parallels Virtuozzo Containers Philosophy ............................................................. 15

About Parallels Virtuozzo Containers Software ............................................................... 15

What is Parallels Virtuozzo Containers ................................................................................... 16

What is Container .................................................................................................................. 17

Parallels Virtuozzo Containers Applications ............................................................................ 18

Distinctive Features of Parallels Virtuozzo Containers ...................................................... 19

OS Virtualization .................................................................................................................... 19

Using Virtuozzo File System ................................................................................................... 20

Templates ............................................................................................................................. 20

Resource Management ......................................................................................................... 21

Main Principles of Parallels Virtuozzo Containers Operation ............................................ 21

Basics of Parallels Virtuozzo Containers Technology ............................................................. 22

Parallels Virtuozzo Containers Configuration .......................................................................... 24

Parallels Virtual Automation Overview .................................................................................... 25

Parallels Power Panel Overview ............................................................................................. 26

Parallels Management Console Overview .............................................................................. 27

Hardware Node Availability Considerations .................................................................... 28

Operations on Containers ....................................................................................... 29

Creating Containers ...................................................................................................... 29

Before You Begin .................................................................................................................. 30

Choosing a Container ID ....................................................................................................... 31

Choosing an OS EZ Template ............................................................................................... 32

List of Supported Linux Distributions for Containers .............................................................. 33

Creating a Container ............................................................................................................. 34

Contents

Configuring Containers .................................................................................................. 35

Setting Startup Parameters ................................................................................................... 35

Setting Network Parameters .................................................................................................. 36

Setting the root Password for Containers .............................................................................. 37

Starting, Stopping, Restarting, and Querying the Status of Containers ............................ 38

Listing Containers ......................................................................................................... 40

Setting Names for Containers ........................................................................................ 43

Storing Extended Information on Containers .................................................................. 45

Migrating Containers ..................................................................................................... 46

Standard Migration ................................................................................................................ 47

Zero-Downtime Migration ...................................................................................................... 50

Migrating Containers Based on Standard Templates ............................................................. 53

Configuring Non-Root Access for Migrating Containers ......................................................... 54

Moving Containers Within the Hardware Node ............................................................... 55

Copying Containers Within the Hardware Node.............................................................. 58

Backing Up and Restoring Containers ........................................................................... 61

Using vzabackup/vzarestore Utilities ...................................................................................... 62

Restoring Containers Based on Standard Templates ............................................................ 64

Managing Backups in Parallels Management Console ........................................................... 65

Reinstalling Containers ................................................................................................ 104

Customizing Container Reinstallation ................................................................................... 106

Deleting Containers ..................................................................................................... 108

Disabling Containers ................................................................................................... 110

Suspending Containers ............................................................................................... 112

Running Commands in Containers .............................................................................. 114

Updating Containers ................................................................................................... 115

Updating EZ Template Packages In Containers ................................................................... 116

Updating OS EZ Template Caches ...................................................................................... 118

Managing Resources ............................................................................................ 120

What are Resource Control Parameters? ..................................................................... 121

Managing Container CPU Resources ........................................................................... 122

Configuring CPU Units ......................................................................................................... 122

Configuring Number of CPUs .............................................................................................. 123

Configuring CPU Limits ....................................................................................................... 125

Contents

Controlling Container CPU Usage With VZASysD Plug-in .................................................... 128

Configuring Containers to Run on Specific CPUs ................................................................ 130

Managing Network Accounting and Bandwidth ............................................................ 131

Network Traffic Parameters ................................................................................................. 132

Configuring Network Classes .............................................................................................. 133

Viewing Network Traffic Statistics ........................................................................................ 135

Turning On and Off Network Bandwidth Management ........................................................ 136

Configuring Network Bandwidth Management for Containers ............................................. 139

Managing Memory Parameters for Containers.............................................................. 141

Configuring Main VSwap Parameters .................................................................................. 142

Configuring the Memory Allocation Limit .............................................................................. 143

Tuning VSwap ..................................................................................................................... 144

Configuring Legacy Containers ............................................................................................ 145

Managing Disk Quotas ................................................................................................ 146

What are Disk Quotas? ........................................................................................................ 146

Disk Quota Parameters ....................................................................................................... 147

Turning On and Off Per-Container Disk Quotas ................................................................... 148

Setting Up Per-Container Disk Quota Parameters ............................................................... 152

Turning On and Off Second-Level Quotas for Containers .................................................... 154

Setting Up Second-Level Disk Quota Parameters ............................................................... 156

Checking Quota Status ....................................................................................................... 158

Cleaning Up Containers ....................................................................................................... 160

Managing Disk I/O Parameters .................................................................................... 162

Configuring Container Disk I/O Priority Levels ...................................................................... 163

Configuring the Disk I/O Bandwidth for Containers .............................................................. 165

Configuring the Number of I/O Operations Per Second ....................................................... 166

Viewing Disk I/O Statistics for Containers ............................................................................ 167

Detecting Disk I/O Bottlenecks ............................................................................................ 168

Setting Disk I/O Limits for Backups and Migrations ............................................................. 170

Managing Container Resources Configurations ............................................................ 171

Splitting the Hardware Node Into Equal Pieces .................................................................... 172

Scaling Container Configuration .......................................................................................... 174

Validating Container Configuration ....................................................................................... 176

Applying New Configuration Samples to Containers ............................................................ 178

Contents

Real-Time Monitoring in Parallels Virtuozzo Containers ...................................... 180

Monitoring Resources with Console ............................................................................. 181

Monitoring Resources with Parallels Management Console .......................................... 183

Using Charts Representation ............................................................................................... 184

Using Table Representation ................................................................................................. 191

Subscribing to Parallels Management Console Alerts ................................................... 192

Managing Services and Processes ...................................................................... 196

What Are Services and Processes ............................................................................... 197

Main Operations on Services and Processes................................................................ 198

Managing Processes and Services .............................................................................. 199

Viewing Active Processes and Services ............................................................................... 200

Monitoring Processes in Real Time ...................................................................................... 203

Changing Services Mode..................................................................................................... 206

Determining Container Identifiers by Process IDs ................................................................ 207

Starting, Stopping, and Restarting Services ........................................................................ 208

Managing Parallels Virtuozzo Containers Network .............................................. 210

Managing Network Adapters on the Hardware Node ................................................... 211

Listing Adapters .................................................................................................................. 212

Creating a VLAN Adapter .................................................................................................... 214

Connecting Adapters to Virtual Networks ............................................................................ 216

Managing Virtual Networks .......................................................................................... 217

Creating a Virtual Network ................................................................................................... 218

Listing Virtual Networks ....................................................................................................... 220

Deleting a Virtual Network ................................................................................................... 221

Managing Virtual Network Adapters ............................................................................. 222

Container Networking Modes .............................................................................................. 222

Creating and Deleting veth Network Adapters ..................................................................... 226

Configuring veth Adapter Parameters .................................................................................. 228

Connecting Containers to Virtual Networks ......................................................................... 231

Managing Private Networks and Subnetworks ............................................................. 233

Learning Private Networks ................................................................................................... 234

Setting Up Private Networks ................................................................................................ 238

Contents

Managing Hardware Nodes .................................................................................. 240

Managing Parallels Virtuozzo Containers Licenses ........................................................ 240

Understanding Licenses ...................................................................................................... 241

Installing Licenses................................................................................................................ 242

Updating Licenses ............................................................................................................... 245

Transferring Licenses to Another Node ................................................................................ 246

Viewing the Current License ................................................................................................ 247

Managing Files ............................................................................................................ 250

Uploading Files to the Hardware Node ................................................................................ 252

Downloading Files to the Local Computer ........................................................................... 255

Setting Permissions for Files on the Node ........................................................................... 256

Updating the Parallels Virtuozzo Containers Software ................................................... 257

Updating Parallels Virtuozzo Containers With vzup2date ..................................................... 258

Updating in Graphical Mode ................................................................................................ 259

Updating in Command-Line Mode ...................................................................................... 266

Using Parallels Management Console to Update Parallels Virtuozzo Containers Software ... 266

Advanced Tasks .................................................................................................... 273

Configuring Capabilities ............................................................................................... 273

Creating VZFS Symlinks Inside a Container ......................................................................... 274

Available Capabilities for Containers .................................................................................... 275

Migrating a Physical Server to a Container ................................................................... 277

Migration Overview .............................................................................................................. 278

Migration Steps ................................................................................................................... 279

Migration Requirements....................................................................................................... 281

Migration Restrictions .......................................................................................................... 282

Migrating in Command Line ................................................................................................. 283

Creating Customized Containers ................................................................................. 290

Using Customized OS EZ Templates ................................................................................... 291

Using EZ OS Template Sets ................................................................................................ 293

Using Customized Application Templates ............................................................................ 295

Contents

Changing System Time From Containers ..................................................................... 297

Setting Up an iSCSI Environment in Parallels Virtuozzo Containers Systems ................. 298

Obtaining the Hardware Node ID From Containers ....................................................... 299

Mounting the /vz Partition via the Parallels Virtuozzo Containers Script ......................... 300

Managing Mount Points In Containers ......................................................................... 301

Preserving Application Data During Container Reinstallation ......................................... 303

Accessing Devices From Inside Containers .................................................................. 305

Moving Network Adapters to Containers ...................................................................... 307

Enabling VPN for Containers........................................................................................ 308

Managing Hardware Node Resources Parameters ....................................................... 309

Setting Immutable and Append Flags for Container Files and Directories ...................... 310

Creating Local Repository Mirrors for vzup2date .......................................................... 310

Parallels Virtuozzo Containers Repository Structure............................................................. 311

Creating a Local Mirror ........................................................................................................ 313

Choosing Updates for Downloading .................................................................................... 316

Managing iptables Modules ......................................................................................... 317

Loading iptables Modules to the Hardware Node ................................................................ 318

Sharing a File System Among Containers ..................................................................... 319

Creating Configuration Files for New Linux Distributions ............................................... 321

Rebooting Containers .................................................................................................. 322

Managing Graphical Applications In Containers ............................................................ 322

Running Graphical Applications in X Windows ..................................................................... 323

Running Graphical Applications via VNC ............................................................................. 329

Contents

Assigning External IP Addresses to Containers ............................................................ 331

Mastering Parallels Management Console ........................................................... 332

Configuring Offline Management Parameters ............................................................... 333

Viewing Summary Pages ............................................................................................. 336

Managing Users and Groups In Containers .................................................................. 337

Configuring Firewall ..................................................................................................... 339

Managing Mount Points............................................................................................... 341

Viewing System and Parallels Virtuozzo Containers Logs .............................................. 342

Managing Files In Containers ....................................................................................... 344

Searching for Containers ............................................................................................. 346

Managing Container Search Domains .......................................................................... 347

Troubleshooting .................................................................................................... 348

General Considerations ............................................................................................... 349

Kernel Troubleshooting ................................................................................................ 351

Using ALT+SYSRQ Keyboard Sequences ........................................................................... 351

Saving Kernel Faults (OOPS) ............................................................................................... 352

Finding a Kernel Function That Caused the D Process State ............................................... 353

Problems With Container Management ........................................................................ 353

Failure to Start a Container .................................................................................................. 354

Failure to Access a Container From Network ....................................................................... 355

Failure to Log In to a Container ............................................................................................ 355

Failure to Back Up a Container in Parallels Management Console ....................................... 356

Failure to Display the List of Container Backups .................................................................. 356

Miscellaneous Problems .............................................................................................. 357

Corrupted Pseudographics in Parallels Virtuozzo Containers Utilities ................................... 357

Timeout When Accessing Remote Hosts ............................................................................ 357

Failure to Start iptables Modules After Physical Server Migration ......................................... 358

Getting Technical Support ........................................................................................... 358

Getting Assistance With Parallels Virtuozzo Containers Installation ...................................... 359

Preparing and Sending Questions to Technical Support ...................................................... 360

Submitting a Problem Report to Technical Support ............................................................. 361

Establishing a Secure Channel to Parallels Support ............................................................. 364

Setting Up the Monitor Node ....................................................................................... 365

Configuring a Serial Console on the Monitor Node .............................................................. 366

Contents

Setting Up netconsole ......................................................................................................... 370

Preparing the Monitor Node for Sending Alerts .................................................................... 376

Using vzstatrep to Monitor Hardware Nodes ....................................................................... 378

Glossary ................................................................................................................. 379

Index ...................................................................................................................... 382

C HAPTER 1

Introduction

This chapter provides basic information about Parallels Virtuozzo Containers 4.7 and this guide.

In This Chapter

About This Guide ................................................................................................... 11

Getting Help ........................................................................................................... 14

Feedback ............................................................................................................... 14

About This Guide

This guide is meant to provide comprehensive information on Parallels Virtuozzo Containers 4.7— high-end server virtualization software for Linux-based servers. The issues discussed in this guide cover the necessary theoretical conceptions as well as practical aspects of working with Parallels Virtuozzo Containers. The guide will teach you to create and administer Containers (sometimes also called Virtual Environments, or VEs) on servers running the Parallels Virtuozzo Containers software and to employ both graphical and command line interfaces for performing various tasks.

Note: The guide does not familiarize you with the process of installing, configuring, and deploying Parallels Virtuozzo Containers systems. Detailed information on these operations is given in the Parallels Virtuozzo Containers Installation Guide.

According to the task-oriented approach, most topics of this guide are devoted to a particular task and the ways to perform it. However, Parallels Virtuozzo Containers is equipped with as many as three different tools to perform administrative tasks:

• the command-line interface

• Parallels Management Console with the graphical user interface

• Parallels Virtual Automation with the web interface

The given guide describes the ways to administer Parallels Virtuozzo Containers and perform main tasks on Hardware Nodes (servers running the Parallels Virtuozzo Containers software) and in the Container context using Parallels Management Console and the command-line interface. As to Parallels Virtual Automation, it is provided with a comprehensive online help system.

Besides, there is another tool for managing Containers—Parallels Power Panel. This web-based tool is mainly regarded as a means for individual Container users to manage their personal Containers and also has its own online help system.

Introduction

Organization of This Guide

Chapter 2, Parallels Virtuozzo Containers Philosophy, is a must-read chapter that helps you grasp the general principles of Parallels Virtuozzo Containers operation. It provides an outline of Parallels Virtuozzo Containers architecture and main features, of the way Parallels Virtuozzo Containers stores and uses configuration information, and of the Parallels Virtuozzo Containers licensing policy.

Chapter 3, Operations on Containers, describes operations you can perform on Containers: creating and deleting Containers, starting and stopping them, backing up and restoring Containers, and so on. You will also learn how to migrate Containers from one Hardware Node to another.

Chapter 4, Managing Resources, focuses on configuring and monitoring the resource control parameters for Containers. These parameters comprise disk quotas, network accounting and shaping, CPU and system resources.

Chapter 5, Real-Time Monitoring in Parallels Virtuozzo Containers, explains the way to keep track of the resources consumption by running Containers and the Hardware Node itself in real time.

Chapter 6, Managing Services and Processes, describes the operations you can perform on processes and services in Parallels Virtuozzo Containers by using both the command-line utilities and Parallels Management Console graphical interface.

Chapter 7, Managing Parallels Virtuozzo Containers Network, familiarizes you with the Parallels Virtuozzo Containers network structure, enumerates Parallels Virtuozzo Containers networking components, and explains how to manage these components in Parallels Virtuozzo Containersbased systems.

Chapter 8, Managing Hardware Nodes, centers on all those operations you can perform on Hardware Nodes.

Chapter 9, Advanced Tasks, enumerates those tasks that are intended for advanced system administrators who would like to obtain deeper knowledge about Parallels Virtuozzo Containers capabilities.

Chapter 10, Mastering Parallels Management Console, focuses on those tasks that are most comfortably accomplished using not the command-line utilities, but Parallels Management Console graphical interface.

Chapter 11, Troubleshooting, suggests ways to resolve common inconveniences should they occur during your work with the Parallels Virtuozzo Containers software.

Introduction

Preformatted

Saved parameters for Container

Monospace Bold

C:\vzlist -a

Documentation Conventions

Before you start using this guide, it is important to understand the documentation conventions used in it.

The table below presents the existing formatting conventions.

Formatting convention Type of Information Example

Special Bold

Italics

Monospace

Key+Key Key combinations for which the

Items you must select, such as menu options, command buttons, or items in a list.

Titles of chapters, sections, and subsections.

Used to emphasize the importance of a point, to introduce a term or to designate a command-line placeholder, which is to be replaced with a real name or value.

The names of commands, files, and directories.

On-screen computer output in your command-line sessions; source code in XML, C++, or other programming languages.

What you type, as contrasted with on-screen computer output.

user must press and hold down one key and then press another.

Go to the Resources tab.

Read the Basic Administration chapter.

These are the so-called OS templates.

To remove a Container, type vzctl delete ctid.

Use vzctl start to start a Container.

101

Ctrl+P, Alt+F4

Besides the formatting conventions, you should also know about the document organization convention applied to Parallels documents: chapters in all guides are divided into sections, which, in their turn, are subdivided into subsections. For example, About This Guide is a section, and Documentation Conventions is a subsection.

Introduction

Getting Help

In addition to this guide, there are a number of other resources shipped with Parallels Virtuozzo Containers 4.7 that can help you use the product more effectively. These resources include:

• Getting Started With Parallels Virtuozzo Containers 4.7 for Linux. This guide provides basic

information on installing Parallels Virtuozzo Containers 4.7 on your server, creating new Containers, and performing the main operations on them.

• Parallels Virtuozzo Containers 4.7 for Linux Installation Guide. This guide provides exhaustive information on the process of installing, configuring, and deploying your Parallels Virtuozzo Containers system. Unlike the Getting Started With Parallels Virtuozzo Containers 4.7 for Linux guide, it contains a more detailed description of the operations needed to install and set Parallels Virtuozzo Containers to work (e.g., planning the structure of your network and performing the Parallels Virtuozzo Containers unattended installation). Besides, it does not include the description of any Container-related operations.

• Parallels Virtuozzo Containers 4.7 for Linux Templates Management Guide. This guide is meant to provide complete information on Parallels Virtuozzo Containers templates—an exclusive Parallels technology allowing you to efficiently deploy standard Linux applications inside Containers and to greatly save the server resources (physical memory, disk space, and so on).

• Parallels Virtuozzo Containers 4.7 for Linux Reference Guide. This guide is a complete reference on all Parallels Virtuozzo Containers configuration files and command-line utilities.

• Parallels Management Console Help. This help system provides detailed information on Parallels Management Console—a graphical user interface tool for managing Hardware Nodes and Containers.

• Parallels Virtual Automation Online Help. This help system shows you how to work with Parallels Virtual Automation—a tool providing you with the ability to manage Hardware Nodes and Containers with the help of a standard Web browser on any platform.

• Parallels Power Panel Online Help. This help system deals with Parallels Power Panel—a means for administering individual Containers through a common Web browser on any platform.

Feedback

If you spot a typo in this guide, or if you have an opinion about how to make this guide more helpful, you can share your comments and suggestions with us by completing the Documentation Feedback form on our website (http://www.parallels.com/en/support/usersdoc/).

C HAPTER 2

Parallels Virtuozzo Containers Philosophy

This chapter describes the general principles of Parallels Virtuozzo Containers operation. It provides an outline of the Parallels Virtuozzo Containers architecture and lets you understand the Parallels Virtuozzo Containers licensing policy.

In This Chapter

About Parallels Virtuozzo Containers Software ........................................................ 15

Distinctive Features of Parallels Virtuozzo Containers ............................................... 19

Main Principles of Parallels Virtuozzo Containers Operation ..................................... 21

Hardware Node Availability Considerations.............................................................. 28

About Parallels Virtuozzo Containers Software

This section provides general information about the Parallels Virtuozzo Containers software and its applications.

Parallels Virtuozzo Containers Philosophy

What is Parallels Virtuozzo Containers

Parallels Virtuozzo Containers is a patented OS virtualization solution. It creates isolated partitions or Containers on a single physical server and OS instance to utilize hardware, software, data center and management effort with maximum efficiency. The basic Parallels Virtuozzo Containers capabilities are:

• Intelligent Partitioning. Divide a server into as many as hundreds of Containers with full server functionality.

• Complete Isolation. Containers are secure and have full functional, fault and performance isolation.

• Dynamic Resource Allocation. CPU, memory, network, disk and I/O can be changed without rebooting.

• Mass Management. Suite of tools and templates for automated, multi-Container and multiserver administration.

The diagram below represents a typical model of the Parallels Virtuozzo Containers-based system structure:

Parallels

Virtuozzo Containers Philosophy

The Parallels Virtuozzo Containers OS virtualization model is streamlined for the best performance, management, and efficiency. At the base resides a standard Host operating system which can be either Windows or Linux. Next is the virtualization layer with a proprietary file system and a kernel service abstraction layer that ensure the isolation and security of resources between different Containers. The virtualization layer makes each Container appear as a standalone server. Finally, the Container itself houses the application or workload.

The Parallels Virtuozzo Containers OS virtualization solution has the highest efficiency and manageability making it the best solution for organizations concerned with containing the IT infrastructure and maximizing the resource utilization. The Parallels Virtuozzo Containers complete set of management tools and unique architecture makes it the perfect solution for easily maintaining, monitoring, and managing virtualized server resources for consolidation and business continuity configurations.

What is Container

A Container is a virtual private server that is functionally identical to an isolated standalone server:

• Each Container has its own processes, users, files and provides full administrative access.

• Each Container has its own IP addresses, port numbers, filtering and routing rules.

• Each Container can have its own configuration for the system and application software, as well

as its own versions of system libraries. It is possible to install or customize software packages inside a Container independently from other Containers or the host system. Multiple distributions of a package can be run on one and the same server.

• Each Container has its own unique root user with full control over the given Container and full access to other user accounts inside this Container.

Parallels Virtuozzo Containers Philosophy

Parallels Virtuozzo Containers Applications

Parallels Virtuozzo Containers 4.7 can be efficiently applied in a wide range of areas: enterprise server consolidation, web and applications hosting, software development and testing, user training, and so on.

If you administer a number of Linux dedicated servers within an enterprise, you can benefit from the Parallels Virtuozzo Containers solution in the following ways:

• Reduce the number of required physical servers and corresponding support by grouping a multitude of your enterprise servers onto a single server without losing a bit of valuable information and without compromising performance.

• Increase server utilization and maximize server potential.

• Provision servers in minutes by using the technology of Parallels Virtuozzo Containers

templates.

• Migrate Containers in the time of network data transfer, nearly eliminating the planned downtime and enabling fast reaction to unplanned downtime situations.

• Monitor OS and application versions and update/upgrade the current software easily across all of your physical servers running the Parallels Virtuozzo Containers software and their Containers.

• Guarantee Quality-of-Service in accordance with a corporate service level agreement (SLA).

• Automate routine tasks such as upgrades and updates.

• Minimize software license and support requirements.

Due to its unique efficiency and completeness, Parallels Virtuozzo Containers has also a wide variety of profitable uses for hosting service providers allowing them to:

• Provide complete self-administration panels (Parallels Power Panel) including system backup/restore and monitoring tools.

• Have a multitude of customers with their individual full-featured Containers sharing a single physical server.

• Transparently move customers and their environments between servers, without any manual reconfiguration.

• Increase profitability through the better management and leverage of hardware and software investments.

• Automate service provisioning by using the technology of Parallels Virtuozzo Containers templates.

Besides, Parallels Virtuozzo Containers proves invaluable for IT educational institutions that can now provide every student with a personal Linux server, which can be monitored and managed remotely. Software development companies may use Containers for testing purposes and the like.

Parallels

Virtuozzo Containers Philosophy

Distinctive Features of Parallels Virtuozzo Containers

The concept of Parallels Virtuozzo Containers is distinct from the concept of traditional virtual machines in the respect that Containers always run the same OS kernel as the host system (that is, Linux on Linux or Windows on Windows). This single-kernel implementation technology allows you to run Containers with a near-zero overhead. Thus, Parallels Virtuozzo Containers offer an order of magnitude higher efficiency and manageability than traditional virtualization technologies.

OS Virtualization

From the point of view of applications and Container users, each Container is an independent system. This independence is provided by a virtualization layer in the kernel of the host OS. Note that only a negligible part of the CPU resources is spent on virtualization (around 1-2%). The main features of the virtualization layer implemented in Parallels Virtuozzo Containers are the following:

• Container looks like a normal Linux system. It has standard startup scripts, software from vendors can run inside Container without Parallels Virtuozzo Containers-specific modifications or adjustment.

• A user can change any configuration file and install additional software.

• Containers are fully isolated from each other (file system, processes, Inter Process

Communication (IPC), sysctl variables).

• Containers share dynamic libraries, which greatly saves memory.

• Processes belonging to a Container can be scheduled for execution on all available CPUs.

Consequently, Containers are not bound to only one CPU and can use all available CPU power.

Parallels Virtuozzo Containers Philosophy

Using Virtuozzo File System

Virtuozzo File System (VZFS) is a legacy file system that allows sharing common files among multiple Containers without sacrificing flexibility. Container users can modify, update, replace, and delete shared files. When a user modifies a shared file, VZFS creates a private copy of that file transparently for the user. Thus, modifications do not affect other users of the same file.

Although VZFS can help you save disk space and memory, it also has a number of limitations:

• You cannot store Containers using VZFS in Parallels Cloud Storage clusters.

• To migrate or restore a Container, you always need to have a corresponding OS template

installed on the destination server.

• VZFS-based Containers lack some functionality provided by Parallels Virtuozzo Containers 4.7 (like creating and managing snapshots).

Note: For more information on VZFS, see the documentation for Parallels Server Bare Metal 5.0.

Templates

A template (or a package set) in Parallels Virtuozzo Containers is a set of original application files repackaged for mounting over Virtuozzo File System. Usually, it is just a set of RPM packages for Red Hat like systems. Parallels Virtuozzo Containers provides tools for creating templates, installing, upgrading, adding them to and removing them from a Container. Using templates lets you:

• Share the RAM among similar applications running in different Containers to save hundreds of megabytes of memory.

• Share the files comprising a template among different Containers to save gigabytes of disk space.

• Deploy applications simultaneously in many Containers.

• Use different versions of an application in different Containers (for example, perform an upgrade

only in certain Containers).

There are two types of templates in Parallels Virtuozzo Containers 4.7. These are OS templates and application templates. An OS template is an operating system and the standard set of applications to be found right after the installation. Parallels Virtuozzo Containers uses OS templates to create new Containers with a preinstalled operating system. An application template is a set of repackaged software packages optionally accompanied with configuration scripts. Parallels Virtuozzo Containers uses application templates to add extra software to an existing Container. For example, you can create a Container on the basis of the CentOS 5 OS template and add the MySQL application to it using the MySQL application template.

For detailed information on Parallels Virtuozzo Containers templates, see the Parallels Virtuozzo Containers 4.7 Templates Management Guide.

Parallels

Virtuozzo Containers Philosophy

Resource Management

Parallels Virtuozzo Containers resource management controls the amount of resources available to Containers. The controlled resources include such parameters as CPU power, disk space, a set of memory-related parameters. Resource management allows Parallels Virtuozzo Containers to:

• effectively share available Hardware Node resources among Containers

• guarantee Quality-of-Service in accordance with a service level agreement (SLA)

• provide performance and resource isolation and protect from denial-of-service attacks

• simultaneously assign and control resources for a number of Containers

• manage a multitude of Hardware Nodes in a unified way by means of Parallels Management

Console and Parallels Virtual Automation

• collect usage information for system health monitoring

Resource management is much more important for Parallels Virtuozzo Containers than for a standalone server since server resource utilization in a Parallels Virtuozzo Containers-based system is considerably higher than that in a typical system.

Main Principles of Parallels Virtuozzo Containers Operation

This section describes the basics of Parallels Virtuozzo Containers technology and discusses the main tools for managing Parallels Virtuozzo Containers-based systems.

Parallels Virtuozzo Containers Philosophy

Basics of Parallels Virtuozzo Containers Technology

In this section, we will try to let you form a more or less precise idea of the way the Parallels Virtuozzo Containers software operates on your computer. Please see the figure below:

Parallels

Virtuozzo Containers Philosophy

This figure presumes that you have a number of physical servers united into a network. In fact, you may have only one dedicated server to effectively use the Parallels Virtuozzo Containers software for the needs of your network. If you have more than one Parallels Virtuozzo Containers-based physical server, each one of the servers will have a similar architecture. In Parallels Virtuozzo Containers terminology, such servers are called Hardware Nodes (or just Nodes), because they represent hardware units within a network.

Parallels Virtuozzo Containers 4.7 is installed on a Linux operating system configured in a certain way. For example, such customized configuration should include the creation of a /vz partition, which is the basic partition for hosting Containers and which must be way larger than the root partition.

Note: For the full list of supported operating systems and detailed instructions on installing Linux (called

Host Operating System in the picture above) on physical servers, see the Parallels Virtuozzo Containers

4.7 Installation Guide.

Once Parallels Virtuozzo Containers is installed, you can run Parallels Virtuozzo Containers services supporting virtualization on your server. This support is presented above as Parallels Virtuozzo Containers Layer. The Parallels Virtuozzo Containers layer ensures that Containers, sharing the same Hardware Node and the same OS kernel, are isolated from each other. A Container is a kind of ‘sandbox’ for processes and users.

Before you are able to create a Container, you need to install the corresponding OS template in Parallels Virtuozzo Containers 4.7. This is displayed as Parallels Templates in the scheme above. Different Containers can be based on different OS templates and thus run different version of Linux (for example, Ubuntu 10.4 or Fedora 13). Once you install at least one OS template, you can create any number of Containers with the help of various Parallels management tools (the Parallels Virtuozzo Containers command-line tools, Parallels Virtual Automation, or Parallels Management Console), configure their network and/or other settings, and work with these Containers as with fully functional LInux servers.

Parallels Virtuozzo Containers Philosophy

Parallels Virtuozzo Containers Configuration

Parallels Virtuozzo Containers 4.7 allows you to flexibly configure various settings for your Parallels Virtuozzo Containers system in general as well as for each and every Container. Among these settings are disk and user quota, network parameters, default file locations and configuration sample files, and others.

Parallels Virtuozzo Containers stores the configuration information in two types of files: the global configuration file /etc/vz/vz.conf and Container configuration files /etc/vz/conf/<CT_ID>.conf. The global configuration file defines global and default parameters for Container operation, for example, logging settings, enabling and disabling disk quota for Containers, the default configuration file and OS template on the basis of which a new Container is created, and so on. On the other hand, a Container configuration file (/etc/vz/conf/CT_ID) defines the parameters for a particular Container, such as disk quota and allocated resources limits, IP address and host name, and so on. If a parameter is configured in both the global configuration file and the Container configuration file, the Container configuration file takes precedence. For the list of parameters that can be configured in the global and Container configuration files, see the Parallels Virtuozzo Containers 4.7 Reference Guide.

The configuration files are read when the Parallels Virtuozzo Containers software and/or Containers are started. However, Parallels Virtuozzo Containers standard utilities (for example, vzctl) allow you to change many configuration settings “on-the-fly”, either without modifying the corresponding configuration files or with their modification (if you want the changes to apply the next time the Parallels Virtuozzo Containers software and/or Containers are started).

Some Parallels Virtuozzo Containers utilities have their own configuration files. For example, vzbackup, which is responsible for backing up Container private areas and configuration files, has its own global configuration file /etc/vzbackup.conf and can have a number of per-Node configuration files located in the backup directory. This directory is defined in the backup global configuration file. Both the global backup configuration file and per-Node ones are located on a central Backup Node. There are a number of other specific configuration files. All of them are described in detail in the Parallels Virtuozzo Containers 4.7 Reference Guide.

Parallels

Virtuozzo Containers Philosophy

Parallels Virtual Automation Overview

Parallels Virtual Automation is designed for Hardware Node administrators and provides them with the ability to manage multiple Hardware Nodes and all Containers residing on them with the help of a standard web browser on any platform. The list of supported browsers is given below:

• Internet Explorer 6 and above

• Firefox 2.0 and above

• Safari 3.0 and above

Chances are that you will also be able to use other browsers, but Parallels Virtuozzo Containers has not been extensively tested with them.

The Parallels Virtual Automation interface has been designed to let the Parallels Virtuozzo Containers server administrator quickly perform all possible tasks through an intuitive navigation system:

Parallels Virtuozzo Containers Philosophy

The main components the Parallels Virtual Automation interface include:

• The left menu frame listing and allowing to access all your Hardware Nodes and Containers and the main types of operations to be performed on them with the help of Parallels Virtual Automation.

• The toolbar on top of the right frame allowing to perform on your Hardware Nodes and Containers the actions most frequently called for in your routine management work and, when necessary, a few more buttons allowing to perform additional actions on the objects listed in the content part of the right frame (Container backups, packages updates, etc.).

• The content part on the right frame displaying the currently accessed Hardware Nodes or Containers, the key information (their statuses, configuration, etc.) and links to advanced actions.

Note: Detailed information on Parallels Virtual Automation is given in its comprehensive online help system and the Parallels Virtual Automation Administrator's Guide.

Parallels Power Panel Overview

Wherever Parallels Virtuozzo Containers is applied, there are people who are supposed to be administrators of particular Containers only, with no access rights to Hardware Nodes. Such people can be subscribers to a hosting provider, university students, administrators of a particular server within an enterprise, etc. Personal Containers can be managed with the help of Parallels Power Panel. Power Panel is a means for administering personal Containers through a common browser: Internet Explorer, Mozilla, and others. It allows Container administrators to do the following:

• Start, stop, or restart the Container.

• Back up and restore the Container.

• Change the Administrator password of the Container.

• Start, stop, or restart certain services inside the Container.

• View the processes currently running in the Container and send signals to them.

• View the current resources consumption and resources overusage alerts.

• Connect to the Container by means of RDP.

• View the system logs.

For more information on Parallels Power Panel, see its online help system.

Note: Apart from Parallels Power Panel, Container administrators are able to use the standard Windows Remote Desktop Connection (RDP) or MS Terminal Service Client (MS TSC) to connect to their Containers and work inside them.

Parallels

Virtuozzo Containers Philosophy

Parallels Management Console Overview

Parallels Management Console is a remote management tool for Parallels Virtuozzo Containers with a graphical user interface. You can use to control Hardware Nodes, to manage Containers, and to monitor the system. The main window of Management Console consists of two parts: the tree pane on the left, and view pane on the right. There is a list of Hardware Nodes in the tree pane. The Hardware Node subtree represents various aspects of its management, for example, Logs, Services, and Templates. The content of the view pane depends on the selected item in the tree pane.

Parallels Virtuozzo Containers Philosophy

Below the view pane on the right, there is also a small Actions/Messages/Operations pane. You can switch between the modes by clicking the corresponding buttons to the right of this pane. The Actions pane displays the progress of Parallels Management Console actions. The Messages pane displays the detailed diagnostics of various Management Console errors. The Operations pane shows the result of various asynchronous tasks performed with Hardware Nodes and their Containers.

Parallels Management Console uses a typical client/server architecture. The client Management Console program runs on Microsoft Windows XP/2003/2008/2008 R2. The client application with the graphical user interface connects to the Parallels Agent software, which is running on the Hardware Node. Parallels Agent communicates with the client via the well-documented open Parallels Agent XML API and controls the Hardware Node itself and its Containers.

The client can control multiple Hardware Nodes simultaneously by connecting to multiple Parallels Agents. As the communications between the client and Parallels Agents are secure, the Management Console workstation may be located virtually anywhere on the network.

More detailed information on installing Parallels Management Console is given in the Parallels Virtuozzo Containers 4.7 Installation Guide.

Hardware Node Availability Considerations

Hardware Node availability is more critical than the availability of a typical server. Since it runs multiple Containers providing a number of critical services, Hardware Node outage may be very costly. Hardware Node outage can be as disastrous as the simultaneous outage of a number of servers running critical services.

To increase the availability of your Hardware Node, we suggest you follow the recommendations below:

• Use RAID storage for critical Container private areas. Do prefer hardware RAID, but software mirroring RAID might suit too as a last resort.

• Do not run software on the Hardware Node itself. Create special Containers where you can host necessary services such as BIND, FTPD, HTTPD, and so on. On the Hardware Node itself, you need only the SSH daemon. Preferably, the Node should accept connections from a predefined set of IP addresses only.

• Do not create users on the Hardware Node itself. You can create as many users as you need in Containers. Remember: compromising the Hardware Node means compromising all Containers as well.

C HAPTER 3

Operations on Containers

This chapter describes how to perform day-to-day operations on Containers.

Note: We assume that you have successfully installed, configured, and deployed your Parallels Virtuozzo Containers system. If you have not, refer to the Parallels Virtuozzo Containers 4.7 Installation Guide.

In This Chapter

Creating Containers ................................................................................................ 29

Configuring Containers ........................................................................................... 35

Starting, Stopping, Restarting, and Querying the Status of Containers ..................... 38

Listing Containers ................................................................................................... 40

Setting Names for Containers ................................................................................. 43

Storing Extended Information on Containers ............................................................ 45

Migrating Containers ............................................................................................... 46

Moving Containers Within the Hardware Node ......................................................... 55

Copying Containers Within the Hardware Node ....................................................... 58

Backing Up and Restoring Containers ..................................................................... 61

Reinstalling Containers ............................................................................................ 104

Deleting Containers ................................................................................................. 108

Disabling Containers ............................................................................................... 110

Suspending Containers ........................................................................................... 112

Running Commands in Containers .......................................................................... 114

Updating Containers ............................................................................................... 115

Creating Containers

This section guides you through the process of creating a Container. We assume that you have successfully installed Parallels Virtuozzo Containers and prepared at least one OS EZ template. If you do not have any OS EZ templates prepared for creating Containers, see the Parallels Virtuozzo Containers 4.7 Templates Management Guide first.

Operations on Containers

Before You Begin

Before you start creating a Container, do the following:

• Check that the Hardware Node is visible on your network. You should be able to connect to/from other hosts. Otherwise, Containers will not be accessible from other servers.

• Check that you have at least one IP address per Container and the addresses belong to the same network as the Hardware Node or routing to the Containers has been set up via the Hardware Node.

To create a new Container, you need to complete the following tasks:

1 Choose an ID for the Container.

2 Choose an OS template for the Container.

3 Create the Container.

Operations on Containers

Choosing a Container ID

Every Container has a numeric ID, also known as Container ID, associated with it. The ID is a 32-bit integer number beginning with zero and unique for a given Hardware Node. When choosing an ID for a Container, follow the simple guidelines below:

• ID 0 is used for the Hardware Node itself. You cannot and should not try to create a Container with ID 0.

• The Parallels Virtuozzo Containers software reserves the IDs ranging from 0 to 100. Do not create Containers with IDs below 101.

The only strict requirement for a Container ID is to be unique for a particular Hardware Node. However, if you are going to have several computers running Parallels Virtuozzo Containers 4.7, we recommend assigning different Container ID ranges to them. For example, on Hardware Node 1 you create Containers within the range of IDs from 101 to 1000; on Hardware Node 2 you use the range from 1001 to 2000, and so on. This approach makes it easier to remember on which Hardware Node a Container has been created, and eliminates the possibility of Container ID conflicts when a Container is migrated from one Hardware Node to another.

Another approach to assigning Container IDs is to follow some pattern of Container IP addresses. Thus, for example, if you have a subnet with the 10.0.x.x address range, you may want to assign ID 17015 to the Container with IP address 10.0.17.15, ID 39108 to the Container with IP address

10.0.39.108, and so on. You can also think of your own patterns for assigning Container IDs

depending on the configuration of your network and your specific needs.

Before you decide on a new Container ID, you may want to make sure that no Container with this ID has yet been created on the Node. The easiest way to check this is to run the following command:

# vzlist -a 101

Container not found

This output shows that Container 101 does not exist on the Node; otherwise it would be present in the list.

If you use Parallels Management Console, click on the name of your Hardware Node in the left pane and then on the Parallels Virtuozzo Containers item. The Management Console right pane will display the list of Containers existing on the Node.

WARNING! When deciding on a Container ID, do not use IDs that were once assigned to Containers unless you are sure that no data belonging to the old Containers remains on the Node. Otherwise, the administrator of the newly-created Container may get access to this data—that is, to the backups of the old Container, its logs, statistics, and so on.

Operations on Containers

Choosing an OS EZ Template

Before starting to create a Container, you need to choose the OS EZ template to base the Container on. You can have several OS EZ templates installed on the Node and prepared for the Container creation. Use the vzpkg list command to see all available OS templates:

# vzpkg list -O

centos-5-x86_64 2011-04-21 23:59:44 fedora-core-13-x86_64 2011-04-11 12:45:52

The -O option passed to the vzpkg list command allows you to list only OS EZ templates installed on the Node. As you can see, two OS templates—centos-5-x86_64 and fedora- core-13-x86_64—are currently available on the server. The time displayed beyond OS EZ templates indicates when these templates were cached.

You can also use the --with-summary option to display brief information on the installed OS EZ templates:

# vzpkg list -O --with-summary

centos-5-x86_64 :CentOS 5 (for AMD64/Intel EM64T) EZ OS template fedora-core-13-x86 :Fedora 13 (for AMD64/Intel EM64T) EZ OS template

For more information on the vzpkg list command, see the Parallels Virtuozzo Containers 4.7 Reference Guide.

In Parallels Management Console, you can click the Templates item under the corresponding Hardware Node name and then the OS Templates tab to see the list of the installed OS templates.

Operations on Containers

List of Supported Linux Distributions for Containers

The current version of Parallels Virtuozzo Containers allows you to create Containers running the following Linux distributions:

• Red Hat Enterprise Linux 5.6 and 6.x

• CentOS 5.6 and 6.x

• Debian 5.0 and 6.0

• Fedora 14

• OpenSUSE 11 with Service Packs 4

• SUSE Linux Enterprise Server 10 and 11

• Ubuntu 10.04, 10.10, and 11.04

Operations on Containers

Creating a Container

Once you choose the Container ID and OS EZ template, you can create the Container private area using the vzctl create command. A private area is the directory containing the VZFS symlinks, copy-on-write area, and private files of the given Container. The private area is mounted to the /vz/root/CT_ID directory on the Hardware Node and provides Container users with a complete Linux file system tree.

The vzctl create command requires only the Container ID and the name of the OS template as arguments. However, to avoid setting all the Container resource control parameters after creating the private area, you can specify a sample configuration to be used for the new Container. All sample configuration files are stored in the /etc/vz/conf directory and have names with the following mask: ve-<configname>.conf-sample. The most commonly used sample is the ve-basic.conf-sample file. this sample file has resource control parameters suitable for most Containers.

Thus, for example, you can create a new Container by executing the following command:

# vzctl create 101 --ostemplate redhat-el5-x86 -–config basic

Creating Container private area (redhat-el5-x86) Container is mounted Postcreate action done Container is unmounted Container private area was created Delete port redirection Adding port redirection to Container(1): 4643 8443

This command creates a Container with ID 101, bases it on the redhat-el5-x86 OS EZ template, and takes all necessary configuration parameters from the ve-basic.conf-sample sample configuration file.

If you specify neither an OS template nor a sample configuration, vzctl will try to take the corresponding values from the global configuration file (/etc/vz/vz.conf). So you can set the default values in this file using your favorite text file editor and do without specifying these parameters each time you create a new Container, for example:

DEF_OSTEMPLATE=".redhat-el5-x86" CONFIGFILE="basic"

Now you can create a Container with ID 101 with the following command:

# vzctl create 101

In principle, now you are ready to start your newly created Container. However, typically you need to set its network IP address, hostname, DNS server address and root password before starting the Container for the first time.

Operations on Containers

Configuring Containers

As a rule, the process of configuring a Container includes the following tasks:

• setting Container startup parameters

• setting Container network parameters

• setting Container user passwords

• configuring Quality of Service (Service Level) parameters

For all these tasks, the vzctl set command is used. Using this command for setting Container startup parameters, network parameters, and user passwords is explained later in this subsection. Service Level Management configuration topics are discussed in the Managing Resources

chapter (p. 120).

Setting Startup Parameters

You can use the vzctl set command to set the onboot startup parameter for a Container. Setting this parameter to yes makes the Container automatically boot at the Hardware Node startup. For example, to enable Container 101 to automatically start when you boot the Hardware Node, you can execute the following command:

# vzctl set 101 --onboot yes --save

Saved parameters for Container 101

The onboot parameter will have effect on the next Hardware Node startup.

Operations on Containers

Setting Network Parameters

To make a Container accessible from the network, you need assign a valid IP address and hostname to it and configure a DNS server the Container will use. You may also wish to start the SSH daemon inside the Container. The session below illustrates setting all these network parameters for Container 101:

# vzctl set 101 --hostname server101.parallels.com --save

Hostname for Container set: server101.parallels.com Saved parameters for Container 101

# vzctl set 101 --ipadd 10.0.186.1/24 --save

Adding IP addresses to the pool: 10.0.186.1 Saved parameters for Container 101

# vzctl set 101 --ipadd fe80::20c:29ff:fe01:fb08 --save

Adding IP addresses to the pool: fe80::20c:29ff:fe01:fb08 Saved parameters for Container 101

# vzctl set 101 --nameserver 192.168.1.165 --save

File resolv.conf was modified Saved parameters for Container 101

These commands will configure Container 101 as follows:

• Set IPv4 address 10.0.186.1 with subnet mask 255.255.255.0 and IPv6 address fe80::20c:29ff:fe01:fb08.

Note: You can assign network masks to Containers operating in the venet0 networking mode only if the USE_VENET_MASK parameter in the Parallels Virtuozzo Containers configuration file is set to yes.

• Set the hostname server101.parallels.com.

• Set the DNS server address to 192.168.1.165.

The –-save flag saves all the parameters to the Container configuration file. You can execute the above commands when the Container is running. In this case, if you do not want the applied values to persist, you can omit the –-save option and the applied values will be valid only until the Container shutdown.

To check whether SSH is running inside the Container, you can use the vzctl exec command. This command allows you to execute any commands in the Container context. In Red Hat-based distributions, sshd is dependent on xinetd, so your session may look like the following:

# vzctl start 101

[This command starts Container 101, if it is not started yet]

# vzctl exec 101 service xinetd status

xinetd is stopped

# vzctl exec 101 service xinetd start

Starting xinetd: [ OK ]

# vzctl exec 101 service xinetd status

xinetd is started

The above example assumes that Container 101 is created on the CentOS OS template. For other OS templates, consult their documentation.

For more information on running commands inside a Container from the Hardware Node, see the

Running Commands in Containers subsection (p. 114).

Operations on Containers

Setting the root Password for Containers

Setting the root user password is necessary for connecting to a Container via SSH or Parallels Power Panel. By default, the root account is locked in a newly created Container, and you cannot log in to it. To unlock the root account, you can run the following commands on the Hardware Node:

# vzctl start 101

[This command starts Container 101, if it is not started yet]

# vzctl set 101 --userpasswd root:test

In this example, we set the root password for Container 101 to test. Now you can log in to the Container via SSH as root and administer it in the same way you would administer a standalone Linux server: install additional software, add users, set up services, and so on. The password will be set inside the Container in the /etc/shadow file in an encrypted form and will not be stored in the Container configuration file. Therefore, if you forget the password, you have to reset it. Note that --userpasswd does not requires the --save switch; the password is anyway persistently set for the Container.

While you can create users and set passwords for them using the vzctl exec or vzctl set commands, it is suggested that you delegate user management to Container administrators advising them of the Container root account password.

Operations on Containers

Starting, Stopping, Restarting, and Querying the Status of Containers

A Container can be started up and shut down like an ordinary server. For example, to start Container 101, you can use the following command:

# vzctl start 101

Starting Container ... Container is mounted Adding port redirection to Container(1): 4643 8443 Adding IP address(es): 10.0.186.101 Hostname for Container 101 set: test.parallels.com Container start in progress...

To check the status of a Container, use the vzctl status command:

# vzctl status 101

VEID 101 exist mounted running

The output displays the following information:

• Whether the Container private area exists.

• Whether this private area is mounted.

• Whether the Container is running.

In our case, vzctl reports that Container 101 exists, its private area is mounted, and the Container is running. Alternatively, you can make use of the vzlist utility:

# vzlist 101

CTID NPROC STATUS IP_ADDR HOSTNAME 101 20 running 10.0.186.101 test.parallels.com

The following command is used to stop a Container:

# vzctl stop 101

Stopping Container ... Container was stopped Container is unmounted

vzctl has a two-minute timeout for the Container shutdown scripts to be executed. If the

Container is not stopped in two minutes, the system forcibly kills all the processes in the Container. The Container will be stopped in any case, even if it is seriously damaged. To avoid waiting for two minutes if you know that the Container is corrupt, you can use the --fast switch:

# vzctl stop 101 --fast

Stopping Container ... Container was stopped Container is unmounted

Make sure that you do not use the --fast switch with healthy Containers, as the forcible killing of Container processes may be potentially dangerous.

To restart a Container, you can use the vzctl restart command:

Operations on Containers

# vzctl restart 101

Stopping Container ... Container was stopped Container is unmounted Starting Container ... Container is mounted Adding IP address(es): 10.0.186.101 Container start in progress...

Note: You can also use Container names to start, stop, and restart Containers. For detailed information on Container names, see the Setting Names for Containers section (p. 43).

Operations on Containers

Listing Containers

Sometimes, you may want to get an overview of the Containers existing on the Hardware Node and to get additional information about them: their IP addresses, hostnames, current resource consumption, and so on. In the most general case, you can get the list of all Containers by running the following command:

# vzlist -a

CTID NPROC STATUS IP_ADDR HOSTNAME 1 135 running 10.101.60.79 localhost 101 8 running 10.101.66.1 ct101.parallels.com 102 7 running 10.101.66.159 ct102.parallels.com 103 - stopped 10.101.66.103 ct103.parallels.com

The -a switch tells the vzlist utility to output both running and stopped Containers. By default, only running Containers are shown. The default columns inform you of the Container IDs, the number of running processes inside Containers, their status, IP addresses, and hostnames. You can customize this output as desired by using vzlist command line switches. For example:

# vzlist -o veid,diskinodes.s -s diskinodes.s

CTID DQINODES.S 1 400000 101 200000 102 200000

This shows only running Containers with the information about their IDs and soft limit on disk inodes, with the list sorted by this soft limit. The full list of the vzlist command-line switches and output and sorting options is given in the Parallels Virtuozzo Containers 4.7 Reference Guide.

In Parallels Management Console, you can display the list of all Containers by clicking the Parallels Virtuozzo Containers item.

Operations on Containers

You can see that currently Containers 101, 102, and 103 exist on the Hardware Node. All the Container vital information (its IP address(es), hostname, statuses, etc.) is presented in the table having the following columns:

Column Name Description

ID The ID assigned to the Container.

Name The name assigned to the Container. This name can be used, along with

the Container ID, to perform Container-related operations on the Hardware Node.

Hostname The hostname of the Container.

IP Address The IP address assigned to the Container.

Status The current status of the Container.

Resources The circle opposite the corresponding Container reflects the current state

of the resource parameters consumed by the Container:

• If the resource consumption lies within 90% of the limits defined for the Container, the green circle with a white tick is displayed. It means that the Container experiences no shortage in resources required for the normal course of work.

• If the Container consumes between 90% and 100% of the limits defined for it, the orange circle with a white exclamation mark is displayed.

• If the Container is currently consuming 100% or more of the limits defined for it, the red circle with a white exclamation mark is displayed. A Container is allowed to consume more than 100% of its quota only in extreme situations. If you do not solve the problem in a reasonable time, applications running inside the Container may be denied some of the resources, so application crashes and other problems are most probable.

OS The OS template the Container is based on.

Architecture The system architecture of the Container.

Original Sample The name of the configuration sample the Container is based on.

Description The Container description.

To facilitate working with Containers, you can sort them by different parameters listed in the table above: their ID, type, hostname, status, IP address, and so on. Just click the column with the appropriate name to put Containers in the desired order.

Operations on Containers

Setting Names for Containers

You can assign an arbitrary name to a Container and use it, along with the Container ID, to perform Container-related operations. For example, you can start or stop a Container by specifying the Container name instead of its ID.

You can assign names to Containers using the --name option of the vzctl set command. For example, to set the computer1 name for Container 101, run this command:

# vzctl set 101 --name computer1 --save

Name computer1 assigned Saved parameters for Container 101

You can also set a name for Container 101 by editing its configuration file:

1 Open the configuration file of Container 101 (/etc/vz/conf/101.conf) for editing, and add

the following string to the file:

NAME="computer1"

2 In the /etc/vz/names directory on the Node, create a symbolic link with the name of

computer1 pointing to the Container configuration file. For example:

# ln --symbolic /etc/vz/conf/101.conf /etc/vz/names/computer1

When specifying names for Containers, keep in mind the following:

• Names may contain the following symbols: a-z, A-Z, 0-9, underscores (_), dashes (-), spaces, the symbols from the ASCII character table with their code in the 128-255 range, and all the national alphabets included in the Unicode code space.

• Container names cannot consist of digits only. Otherwise, there would be no way to distinguish them from Container IDs.

• If it contains one or more spaces, the Container name must be put in single or double quotes.

Once you assign the computer1 name to Container 101, you can start using it instead of ID 101 to perform Container-related operations. For example:

• You can stop Container 101 with the following command:

# vzctl stop computer1

Stopping Container ... Container was stopped Container is unmounted

• You can start Container 101 anew by running the following command:

# vzctl start computer1

Starting Container ... ...

You can find out what name is assigned to Container 101 in one of the following ways:

• Using the vzlist utility:

# vzlist -o name 101

NAME computer1

Operations on Containers

• Checking the NAME parameter in the Container configuration file (/etc/vz/conf/101.conf):

# grep NAME /etc/vz/conf/101.conf

NAME="computer1"

• Checking the NAME parameter in the /etc/vz/names/computer1 file which is a symlink to the Container configuration file:

# grep NAME /etc/vz/names/computer1

NAME="computer1"

You can also use Parallels Management Console to set names for Containers:

1 Select the Parallels Virtuozzo Containers item under the corresponding Hardware Node,

right-click the Container, and choose Properties.

2 On the General tab of the displayed window, enter a name in the Name field.

3 Click OK.

Operations on Containers

Storing Extended Information on Containers

Sometimes, it may be difficult to remember the information on certain Containers. The probability of this increases together with the number of Containers and with the time elapsed since the Container creation. Parallels Virtuozzo Containers allows you to set the description for Containers and view it later on, if required. The description can be any text containing any Container-related information; for example, you can include the following in the Container description:

• the owner of the Container

• the purpose of the Container

• the summary description of the Container

Let us assume that you are asked to create a Container for a Mr. Johnson who is going to use it for hosting the MySQL server. So, you create Container 101 and then execute the following command on the Hardware Node:

# vzctl set 101 --description "Container 101 > owner—Mr. Johnson > purpose—hosting the MySQL server" --save

Saved parameters for Container 101

This command saves the following information related to the Container: its ID, owner, and the purpose of its creation. At any time, you can display this information by running the following command:

# vzlist -o description 101

DESCRIPTION Container 101 owner—Mr. Johnson purpose—hosting the MySQL server

You can also view the Container description by checking the DESCRIPTION parameter of the Container configuration file (/etc/vz/conf/101.conf). However, the data stored in this file are more suitable for parsing by the vzlist command rather than for viewing by a human because all symbols in the DESCRIPTION field except the alphanumerical ones ('a-z', 'A-Z', and '0-9'), underscores ('_'), and dots ('.') are transformed to the corresponding hex character code.

When working with Container descriptions, keep in mind the following:

• You can use any symbols you like in the Container description (new lines, dashes, underscores, spaces, and so on).

• If the Container description contains one or more spaces or line breaks (as in the example above), it must be put in single or double quotes.

• Unlike a Container name, a Container description cannot be used for performing Container- related operations (for example, for starting or stopping a Container) and is meant for reference purposes only.

To provide a description for a Container in Parallels Management Console, do the following:

Operations on Containers

1 Select the Parallels Virtuozzo Containers item under the corresponding Hardware Node,

right-click the Container, and choose Properties.

2 On the General tab of the displayed window, type the necessary information in the Description

field.

3 Click OK.

Migrating Containers

A Hardware Node is the system with higher availability requirements in comparison with a typical Linux system. If you are running your company mail server, file server, and web server in different Containers on one and the same Hardware Node, then shutting it down for hardware upgrade will make all these services unavailable at once. To facilitate hardware upgrades and load balancing between Hardware Nodes, Parallels Virtuozzo Containers provides you with the ability to migrate Containers from one physical box to another.

Migrating Containers is possible if Parallels Virtuozzo Containers 4.7 is installed on two or more Hardware Nodes. You can choose one of the two ways to migrate a Container:

• Migrating a Container using the standard migration technology. In this case, there is a short downtime needed to stop and start the Container during its migration from the Source Node to the Destination Node.

• Migrating a Container using the zero downtime migration technology. In this case, the 'stop' and 'start' operations are not performed and the migrated Container is restored on the Destination Node in the same state as it was at the beginning of the migration. This greatly reduces the migration time and puts it on the same footing as the delay caused by a short interruption in the network connectivity.

Both ways are described in the following subsections in detail.

Note: Containers created under the Parallels Virtuozzo Containers x86 version can be migrated to Hardware Nodes running the x86-64 version of Parallels Virtuozzo Containers, but not vice versa.

Operations on Containers

Standard Migration

The standard migration procedure allows you to move both stopped and running Containers. Migrating a stopped Container includes copying all Container private files from one Node to another and does not differ from copying a number of files from one server to another over the network. The migration procedure of a running Container, in turn, is a bit more complicated and can be described as follows:

1 After initiating the migration process, all Container private data is copied to the Destination

Node. During this time, the Container on the Source Node continues running.

2 The Container on the Source Node is stopped.

3 The Container private data copied to the Destination Node is compared with that on the Source

Node, and if any files were changed during the first migration step, they are copied to the Destination Node again and rewrite the outdated versions.

4 The Container on the Destination Node is started.

There is a short downtime needed to stop the Container on the Source Node, copy the Container private data changes to the Destination Node, and start the Container on the Destination Node. However, this time is very short and does not usually exceed one minute.

Note: Before the migration, it may be necessary to detach the Container from its caches. For more information on cached files, see the Cleaning Up Containers subsection (p. 160).

The following session moves Container 101 from the current Hardware Node to a new Node named ts7.parallels.com:

# vzmigrate ts7.parallels.com 101

root@ts7.parallels.com's password: vzmsrc: Connection to destination Hardware Node (ts7.parallels.com) \ is successfully established vzmsrc: Moving/copying Container#101 -> Container#101, [], [] ... vzmsrc: Container migrating mode : first stage sync, with tracking, \ second stage sync, with Container stopping vzmsrc: Syncing private area of Container#101 [/vz/private/101] ... / 100% |*****************************| vzmsrc: done vzmsrc: Stopping Container#101 ... vzmsrc: done vzmsrc: Fast syncing private area of Container#101 [/vz/private/101] ... / 100% |*****************************| vzmsrc: done vzmsrc: DST: Starting Container#101 ... vzmsrc: DST: done vzmsrc: Successfully completed

You can specify more than one Container ID simultaneously. In this case, all specified Containers will be moved to a new Hardware Node one by one.

Important! For the command to be successful, a direct SSH connection (on port 22) must be allowed between the Source and Destination Nodes.

Operations on Containers

By default, once the migration is complete, the Container private area and configuration file on the Source Node are renamed by receiving the .migrated suffix. However, if you want the Container private area on the Source Node to be removed after the successful Container migration, you can override the default vzmigrate behavior by changing the value of the REMOVEMIGRATED variable in the global configuration file (/etc/vz/vz.conf) to yes or by using the –r yes switch of the vzmigrate command.

To migrate one or more Containers using Parallels Management Console, select these Containers from the list in the right pane after clicking the Parallels Virtuozzo Containers item in the left pane. Then right-click the selection, and choose Tasks > Migrate to Another Hardware Node. Note that the Destination Node must be already registered in Management Console; otherwise, the migration option will not be available. The Migrate Containers window appears.

Operations on Containers

In this window, do the following:

• Select the Destination Node where you want to move the Container.

• Make sure that the Offline migration radio button is selected. This option is used to migrate

Containers by means of the standard migration technology.

You can also specify the following options for the Container:

• The Do not start the Container after migration check box, if selected, prevents the migrated Container from starting on the Destination Node after its successful migration. This option does not have any effect if the Container was not running on the Source Node.

• The Force migration check box, if selected, forces the Container migration even if the templates necessary for the Container correct operation are not installed on the Destination Node. However, it will be impossible to start such a Container after the migration in case of the absence of the needed templates.

• Select the Remove the Container private area(s) from the source server after migration check box to delete the Container private area from the Source Node after the Container successful migration.

When you are ready, click the Migrate button.

Operations on Containers

Zero-Downtime Migration

The vzmigrate utility allows you to migrate Containers from one Hardware Node to another with zero downtime. The zero-downtime migration technology has the following main advantages as compared to the standard one:

• The process of migrating a Container to another Node is transparent for you and the Container applications and network connections. That means that no modifications of system characteristics and operational procedures inside the Container are performed on the Source and Destination Nodes.

• The Container migration time is greatly reduced. In fact, the migration eliminates the service outage or interruption for Container end users.

• The Container is restored on the Destination Node in the same state as it was at the beginning of the migration.

• You can move the Containers running a number of applications that you do not want to be rebooted during the migration.

Note: Zero-downtime migration cannot be performed on Containers having one or several opened sessions established with the vzctl enter CT_ID command.

Before performing zero-downtime migration, it is recommended to synchronize the system time on the Source and Destination Nodes, for example, by means of NTP (http://www.ntp.org). The reason for this recommendation is that some processes running in the Container might rely on the system time being monotonic and thus might behave unpredictably if they see an abrupt step forward or backward in the time once they find themselves on the new Node with different system clock parameters.

In the current version of Parallels Virtuozzo Containers, you can use the following types of zerodowntime migration for migrating a Container:

• Simple online migration. In this case, the Container is dumped at the beginning of the migration—that is, all Container private data including the state of all running processes are saved to an image file. This image file is then transferred to the Destination Node where it is undumped.

• Lazy online migration. Using this type of online migration allows you to decrease the size of the dumped image file storing all Container private data and transferred to the Destination Node by leaving the main amount of memory in a locked state on the Source Node and swapping this memory from the Source Node on demand. Thus, the migrated Container can be started before the whole memory is transferred to the Destination Node, which drastically reduces the service delay of the corresponding Container. When a process tries to access a page of memory that has not yet been migrated, the request is intercepted and redirected to the Source Node where this page is stored.

• Iterative online migration. In this case, the main amount of Container memory is transferred to the Destination Node before the Container is dumped and saved to an image file. Using this type of online migration allows you to attain the smallest service delay.

Operations on Containers

• Iterative + lazy online migration. This type of online migration combines the techniques used in both the lazy and iterative migration types when some part of Container memory is transferred to the Destination Node before the Container is dumped and the rest is transported after the Container has been successfully undumped on the Node.

To migrate a Container by using the zero downtime migration technology, use the --online option of the vzmigrate utility. By default, the iterative online migration type is used to move a Container from one Hardware Node to another. For example, you can migrate Container 101 from the current Hardware Node to the Destination Node named my_node.com by executing the following command:

Note: If the CPU capabilities of the Source Node exceed those of the Destination Node (for example, you migrate from a Source Node running the Core 2 Duo processor to a Destination Node running the Pentium 4 processor), the migration may fail and you will be presented with the corresponding warning message. However, if you are sure that the CPU power of the Destination Node is sufficient to start and run the Container being migrated, you can use the -f option to force the migration process.

# vzmigrate --online --require-realtime my_node.com 101

Enter password: Connection to destination Hardware Node (192.168.1.57) \ is successfully established Moving/copying Container#101 -> Container#101, [], [] ... Syncing private area '/vz/private/101'

- 100% |***************************************

done Suspending Container#101 ... done Dumping Container#101 ... done ... Migration completed

The --require--realtime option tells vzmigrate to move the Container by using the

iterative online migration type only. So, if this migration type cannot be carried out, the command will fail and exit. If the --require--realtime option is omitted and the command fails, vzmigrate will try to move the Container by means of the simple online migration. You can specify more than one Container ID simultaneously. In this case, all specified Containers will be moved to a new Hardware Node one by one.

If you want to use another migration type for migrating Containers, you need to pass the following options to vzmigrate:

• Specify the --noiter option to migrate a Container using the simple online migration type.

• Specify the --noiter and --lazy options to migrate a Container using the lazy online

migration type.

• Specify the --lazy option to migrate a Container using the iterative + lazy online migrate type.

Operations on Containers

To migrate one or more Containers in Parallels Management Console, select these Containers from the list in the right pane after selecting the Parallels Virtuozzo Containers item in the left pane. Then right-click the selection, and choose Tasks > Migrate to Another Hardware Node. Note that the Destination Node must be already registered in Parallels Management Console; otherwise, the migration option will not be available. The Migrate Containers window appears.

In this window, do the following:

• Select the Destination Node where you want to move the Container.

• Select the Live migration radio button used to migrate Containers by means of the zero

downtime migration technology. The Container will be migrated using the iterative online migration type.

You can also specify the following options for the Container:

• The Force migration check box, if selected, forces the Container migration even if the templates necessary for the Container correct operation are not installed on the Destination Node. Keep in mind that you will not be able to start such a Container on the Destination Server.

When you are ready, click the Migrate button.

Operations on Containers

Migrating Containers Based on Standard Templates

If you have a Hardware Node running an old version of Parallels Virtuozzo Container (for example, Virtuozzo 3.0), you probably have Containers that are based on standard OS templates and use one or more standard application templates. To migrate such Containers to a Hardware Node running Parallels Virtuozzo Containers 4.7, you need to complete the following tasks:

1 Migrate the OS standard template the Container is based on and all standard applications

templates the Container uses from the Source Node (that is, the Node where the template is installed) to the Destination Node (that is, the Node with Parallels Virtuozzo Containers 4.7 where you plan to migrate Container 101).

2 Migrate the Container from the Source Node to the Destination Node.

The following example shows you how to migrate Container 101. This example assumes the following:

• Container 101 is based on the redhat-as4 OS standard template.

• The postgresql-as4 standard application template is applied to Container 101.

• The Destination Node has the IP address of 192.168.0.197.

Migrating Standard Templates

In the first step, you need to migrate the OS and application standard templates used by Container 101 from the Source to the Destination Node. To do this, execute the following command on the Source Node:

# vzmtemplate 192.168.0.197 redhat-as4 postgresql-as4

root@192.168.0.197's password: Connection to Destination Node (192.168.0.197) is successfully established Copying template "redhat-as4" ...

When executed, the vzmtemplate utility tries to connect to the Destination Node with IP address

192.168.0.197 and copy the specified templates there. By default, vzmtemplate logs in to the

Destination Node as root and asks you for the password of this user. However, you can make the utility use other credentials to log in to the Destination Node. To do this, indicate the desired user name with the @ symbol before the IP address in the command above (for example, user1@192.168.0.123). Keep in mind that the specified user must have the root privileges; otherwise, the command will fail.

To check that the redhat-as4 and postgresql-as4 templates have been successfully copied to the Destination Node, run the following command on this Node:

# vzpkg list

redhat-as4 20100918 postgresql-as4 20100918

As you can see, both templates are now available on the Destination Node.

Operations on Containers

Migrating the Container

Now that you have copied the standard templates, you can migrate Container 101. To do this, run the following command on the Source Node:

# vzmigrate 192.168.0.197 101

root@192.168.0.197's password: vzmsrc: Connection to destination Hardware Node (192.168.0.197) is successfully established vzmsrc: Moving/copying Container#101 -> Container#101, [], [] ... ...

Migrating the Container may take some time; please wait for the command to complete.

Configuring Non-Root Access for Migrating Containers

By default, you need to run the pmigrate utility as the root user to migrate Containers. You can, however, configure your system so that pmigrate can be executed under another account. This process involves editing the /etc/sudoers file on the Node.

Let us assume that you want to run the pmigrate utility under the pmigr_user account. To do this:

1 Open the /etc/sudoers file for editing.

2 Locate the Defaults requiretty string in the file, and comment it:

# Defaults requiretty

3 Locate the following string in the file

root ALL=(ALL) ALL

and replace root with the pmigr_user name:

pmigr_user ALL=(ALL) ALL

4 Save the file.

Operations on Containers

Moving Containers Within the Hardware Node

The vzmlocal utility allows you to move Containers within your Node. Moving a Container within one and the same Node consists in changing the Container ID and its private area and root paths. You can use vzmlocal to change the ID of the corresponding Container only or to additionally modify its private area and root path.

Let us assume that you want to change the ID of your Container from 101 to 111 and modify its private area and root paths from /vz/private/101 to /vz/private/my_dir and from /vz/root/101 to /vz/root/ct111, respectively. To do this, execute the following command on the Node:

# vzmlocal 101:111:/vz/private/my_dir:/vz/root/ct111

Moving/copying Container#101 -> Container#111, [/vz/private/my_dir], [/vz/root/ct111] ... ... Successfully completed

To check if Container 101 has been successfully moved to Container 111, you can use the following commands:

# vzlist -a

CTID NPROC STATUS IP_ADDR HOSTNAME 1 43 running 10.0.10.1 localhost 111 - stopped 10.0.10.101 myContainer

# ls /vz/private

1 my_dir

# ls /vz/root

1 ct111

The commands output shows that the ID of Container 101 has been changed to 111, its private area is now located in the /vz/private/my_dir directory on the Node, and the path to its root directory is /vz/root/ct111.

Notes:

1. You can use the vzmlocal utility to move several Containers simultaneously.

2. You can run the vzmlocal utility on both running and stopped Containers.

In Parallels Management Console, you can move Containers within a Hardware Node using the Move Container wizard. To invoke the wizard, select the Parallels Virtuozzo Containers item under the corresponding Hardware Node name, right-click the Container you want to change the ID of, and choose Tasks > Move Container. The wizard asks you to complete a number of tasks:

1 In the first step, you need to choose between two options:

• The first option (Change Container ID) lets you specify a new ID for the Container in

addition to specifying its new root and private area paths. Note that if you choose this option, you will not be able to preserve the old ID for th Container.

Operations on Containers

• The second option (Change Container location on Hardware Node) allows you to specify

the new root and private area paths without changing the Container ID.

2 If you choose the first option, you have to specify a new ID for the corresponding Container in

the second step of the wizard. Note that the old ID for the Container will be lost and all Container private data will be transferred to the /vz/private/<new_CT_ID> directory where

<new_CT_ID> denotes the new ID assigned to the Container (for example, /vz/private/111 for Container 111).

3 Next, you are presented with the Set New Container Root and Private Area Paths window.

Operations on Containers

This window is displayed in one of the following cases:

• You selected the Change Container ID check box in the first step of the wizard, specified a

new ID for the Container, and clicked Next in the Specify New Container ID window. In this case, the wizard will offer you to use the default paths, but will leave you the possibility to alter these paths. To configure a path, select the corresponding check box, and type the path in the field below the check box. If have made some changes to the default paths and want to revert to these paths, click the Set Default button.

• You selected the Change Container location on Hardware Node check box and clicked

Next in the first step of the wizard. In this case, you can do the following:

- Manually enter the new private and root paths for the Container.

- Click the Set Default button to display and use the paths offered by the wizard.

4 In the last step of the Move Container wizard, you can review the settings made by you in the

previous steps. Click the Finish button to start moving the Container. This may take some time.

Operations on Containers

Copying Containers Within the Hardware Node

Parallels Virtuozzo Containers allows you to create a complete copy of a particular Container (in respect of all the Container data and resources parameters), or a Container clone. This saves your time because you do not have to think of setting up the Container configuration parameters and the like. Moreover, you can create a number of Container clones at a sitting.

In Parallels Virtuozzo Containers-based systems, you can use the vzmlocal utility to copy a Container within the given Hardware Node. For example, you can issue the following command to create Container 111 and make it be a complete copy of Container 101:

Note: You can clone both running and stopped Containers.

# vzmlocal -C 101:111

Moving/copying Container#101 -> Container#111, [], [] ... Syncing private area '/vz/private/101'->'/vz/private/111' ... Successfully completed

# vzlist -a

CTID NPROC STATUS IP_ADDR HOSTNAME 1 42 running 10.0.10.1 localhost 101 10 running 10.0.10.101 Container115 111 - stopped 10.0.10.115 Container115

As you can see from the example above, a clone of Container 101 (i.e. Container 111) has been successfully created. However, before starting to use Container 111, you need to set another IP address and another hostname for this Container which are currently identical to those of Container

101. Please consult the Configuring Containers section (p. 35) to learn how you can do it.

The vzmlocal utility also enables you to override the default private area and root paths of the destination Container which, by default, are set to /vz/private/<dest_CTID> and /vz/root/<dest_CTID>, respectively (where <dest_CTID> denotes the ID of the resulting Container). In the case of Container 111, these paths are /vz/private/111 and /vz/root/111. To define different private area and root paths for Container 111, you can execute the following command:

# vzmlocal -C 101:111:/vz/private/dir_111/:/vz/root/ct111

Moving/copying Container#101 -> Container#111, [], [] ... Syncing private area '/vz/private/101'->'/vz/private/dir_111' ... Successfully completed

# ls /vz/private

1 101 dir_111

# ls /vz/root

1 101 ct111

To clone a Container in Parallels Management Console, click Parallels Virtuozzo Containers under the name of the corresponding Hardware Node, right-click the Container you want to clone, and choose Tasks > Clone Container(s). The Clone Container wizard will guide you through the process of cloning the Container:

Operations on Containers

1 First, you need to specify the number of Container clones to create and the starting Container

ID.

Operations on Containers

Specify the number of clones to create in the Number of Containers to create field. By default, one Container clone is created.

Similarly to creating new Containers, the Clone Container wizard allows the simultaneous creation of several Container clones with IDs in a continuous series only. The default starting Container ID, which is automatically offered, is the first unoccupied ID starting from 101. For example, if you already have Containers with IDs from 101 through 105 and 107, the ID of 106 will be offered by default. And if you are creating only one Container clone, you can safely accept this number. Or you can specify any other number, and the system will check up if the ID is unoccupied. However, if you are going to create a number of Container clones, it is recommended to decide on an unoccupied ID series in advance.

2 In the second step, you are asked to specify a new name and a new hostname for the resulting

Container. Type an arbitrary name you consider suitable for the Container in the Name field and indicate its hostname, if necessary, in the Hostname field.

3 In the Assign Network Settings to Containers window, you can view and configure the virtual

network adapters that will be available inside the Container clone. Detailed information on all network parameters and on the way to manage them is provided in the Configuring Virtual Adapter Parameters subsection.

4 In the next step, you can change the path to the private area and root directory of the Container

clone by selecting the corresponding Override check boxes and entering the desired paths in the fields provided.

5 The last window lets you review the parameters provided by you in the previous steps. You can

also select the Start the cloned Container after its creation check box to immediately start the Container after its successful cloning. Click Finish to start the copying process.

Parallels Management Console also allows you to create several copies of a Container at once. To do this, right-click the Containers to clone in the right pane, choose Tasks > Clone Container(s), and in the displayed window, provide the necessary information for the cloned Containers.

Operations on Containers

Backing Up and Restoring Containers

A regular backing up of the existing Containers is essential for any Hardware Node reliability. Any Container is defined by its private area, configuration files, action scripts, and quota information. Parallels Virtuozzo Containers allows to back up all these components. Each backup file can be of one of the following 3 types:

• A full backup containing all Container data. This kind of backup is the most time-consuming, space-intensive, and the least flexible one. However, full backups are the quickest to restore.

• An incremental backup containing only the files changed since the last full, differential, or incremental backup. Incremental backups record only the changes since the last Container backup (either full, differential, or incremental) and, therefore, are less in size and take less time to complete than the full and differential backups.

• A differential backup containing only the files changed since the last full backup. This kind of backup does not take into account available incremental and differential backup archives and always backs up all the files modified since the last full backup.

Operations on Containers

Using vzabackup/vzarestore Utilities

In Parallels Virtuozzo Containers 4.7, you can use the vzabackup and vzarestore utilities to back up and restore Containers. These utilities can be run on virtually every Node in your network, including

• the Source Node where the Container to be backed up is residing

• the Backup Node—a special Node with Parallels Virtuozzo Containers intended for storing

Container backups

• any other physical server with Parallels Virtuozzo Containers

To successfully run the vzabackup and vzarestore utilities, make sure of the following:

1 A Node where you plan to run the utilities has the vzabackup package installed. You can find

the vzabackup package in the /virtuozzo/RPMS directory of your Parallels Virtuozzo Containers distribution and install it using the rpm -i command.

2 A network connection can be established between the Source and Backup Nodes.

3 Forward and reverse DNS lookups are correctly configured for both the Source and Backup

Nodes.

vzabackup is used to back up Containers. Let us assume the following:

• You want to create a full backup of Container 101 residing on the Source Node with the IP address of 192.168.0.15.

• You can access the Source Node using the source_root user name and the 1234qwer password.

• The backup will be created with the high level of compression.

• The backup will be stored on the Backup Node that you can access using the IP address of

192.168.200.200, the backup_root user name, and the 1qaz2wsx password.

• You want to exclude the /tmp directory in Container 101 from the backup.

• You want to set the following description for the resulting backup archive: The MySQL

database—latest changes.

To create a backup with the aforementioned parameters, you can execute the following command on any Hardware Node with vzabackup installed and having the network connectivity to the Source and Backup Nodes:

# vzabackup -D "The MySQL database—latest changes." -C3 \

--storage backup_root:1qaz2wsx@192.168.200.200 \

source_root:1234qwer@192.168.0.15 -e 101 \

--exclude-files /tmp

Starting backup operation for node '192.168.0.15'... * Operation with the Container ct101 is started * Backing up environment ct101 locally * Checking parameters * Dumping quota

Operations on Containers

* Creating backup 3dec6e78-2f3e-7c4a-a969-f5b27e188783/20101013154047 * Adjusting backup type (full) * Backup storage: receiving backup file * Preparing for backup operation * Backing up private area 100% |**************************************************************| * Sending private backup data * Backup storage: storing private backup data * Backup storage: filling resultant backup info * Operation with the Container ct101 is finished successfully. Backup operation for node '192.168.0.15' was finished successfully.

Once the command is complete, you can find the created backup archive in the backup directory on the Backup Node. By default, this directory is /vz/backups. Later on, you can restore the Container backup from this directory.

You can specify any number of Hardware Nodes IP addresses in the command line. You can also perform an incremental or a differential backup by additionally specifying the -I or --Tdiff option, respectively. If you indicate the –I or --Tdiff option, and the utility cannot find the corresponding full backup, a full backup is created. If you do not specify the Backup Node, the backup will be put to the backup directory on your local Node. Detailed information on all options that can be passed to the vzabackup utility is given in the Parallels Virtuozzo Containers 4.7 Reference Guide.

To restore Containers from their backups, you can use the vzarestore utility. However, before starting to restore Containers, you may want to view the information about your backups. For example, to examine the backups stored on the Backup Node with IP address

192.168.200.200, you can run the following command on this Node (or on any other Node

where the vzabackup package is installed):

# vzarestore --list --storage backup_root:1qaz2wsx@192.168.200.200

Show existing backups... CTID Title Creation date/time Type Size 101 ct101 2010-02-11T111507+0004 full 8.79 Mb ...

If you are running vzarestore on the Backup Node itself, you can omit the --storage option.

To restore Container 101, you can run this command on the Source Node:

# vzarestore 101 --storage backup_root:1qaz2wsx@192.168.200.200

Restore container: Container101 from 1361ac21-4cae-4981-... Container ct101 was restored successfully.

This command restores the latest backup of Container 101 stored on the Backup Node with IP address 192.168.200.200 to the Node where you have run the command (in our case, on the Source Node). If you want to restore a specific (not the latest) Container backup, use the -b option and specify the ID of the backup instead of the Container ID. You can find out the backup ID assigned to a Container backup using the -l and -f options of the vzarestore command. You can also restore only certain files from the backup archive of Container 101 using the --files option. For detailed information on all options that can be used with the vzarestore utility, see the Parallels Virtuozzo Containers 4.7 Reference Guide.

Operations on Containers

Restoring Containers Based on Standard Templates

If you have one or more backups of Containers that are based on standard templates, you can use the following procedure to restore them on Hardware Nodes running Parallels Virtuozzo Containers

4.7 (called the Destination Node):

1 Make sure that the standard OS template and all standard application templates used by the

Container you plan to restore are installed on the Destination Node.

2 Restore the Container.

Installing Standard Templates

To install a standard OS or application template, you can use the rpm -i command. For example, you can use the following command to install the Samba standard template:

# rpm -ivh samba-template-20060211-1.0-1.i386.rpm

Preparing... ################################### [100%] 1:samba-template ################################### [100%]

You can also use the vzmtemplate utility to copy standard templates from one Hardware Node to another. For example, you can copy the redhat-as4 OS template installed on the Source Node to the Destination Node with the IP address of 192.168.0.9 by running this command:

# vzmtemplate root@192.168.0.9 redhat-as4

root@192.168.0.197's password: Connection to Destination Node (192.168.0.9) is successfully established Copying template "redhat-as4" ...

Restoring the Container

Now that all necessary standard templates are available on the Hardware Node with Parallels Virtuozzo Containers 4.7, you can restore the Container. For example, you can run the following command on the Destination Node:

# vzarestore 101 --storage backup_root:1qaz2wsx@192.168.200.200

Restore container: Container101 from 1361ac21-4cae-4981-... Container ct101 was restored successfully.

This command restores the latest backup of Container 101 stored on the Backup Node with IP address 192.168.200.200 to the Destination Node. For more information on restoring Containers, see Backing Up and Restoring Containers (p. 61).

Operations on Containers

Managing Backups in Parallels Management Console

Parallels Management Console deals with three kinds of Nodes - the Source Nodes (the Nodes where Containers are hosted during their backing up); the Backup Nodes (the Nodes where Container backups are stored); and the Destination Nodes (the Nodes where Container backups are restored).

These Nodes are singled out by their functionality only. In reality, one and the same Hardware Node may perform two or even three functions. Usually, the Source and Destination Node are represented by one and the same Hardware Node, because you will likely want the Containers you back up to be restored to their original Node. However, setting up a dedicated Backup Node is recommended.

You should make sure that all the three Nodes are registered in Management Console before starting to work with them.

You can perform the following backup-related operations in Parallels Management Console:

• Assign the default Backup Node for the given Source Node.

• Set the default backup location on the Backup Node.

• Back up a single Container from the Source Node to the Backup Node.

• Back up a number of Containers or all Containers on the Node to the Backup Node.

• Restore a single Container from the Backup Node to the Destination Node.

• Restore a number of Containers or all Containers of a from the Backup Node to the Destination

Node.

• Restore individual files from the Container backup on the Backup Node to the Destination Node.

• Manage the Backup Nodes.

• Search the backup of a given Container from the Source Node across all the Backup Nodes.

• Automate the task of backing up Containers by setting backups to be run on a schedule.

Operations on Containers

Setting Default Backup Parameters

Parallels Virtuozzo Containers allows you to specify a number of default backup parameters that can then be used when creating Container backup archives. These parameters include the following:

• default Backup Node

• default backup location on the Backup Node

• default backup compression level (p. 69)

• default backup type (p. 71)

The following subsections describe in detail how to configure these parameters in Parallels Management Console.

Assigning the Default Backup Node

When backing up Containers from a Source Node, you need specify the Backup Node where the resulting backups will be stored. Parallels Management Console allows you to set the default Backup Node for a given Source Node by doing the following:

1 Right-click the respective Source Node, and choose Backup > Set Default Backup Options.

2 Click the Change button next to the Server field:

Operations on Containers

3 In the Backup Storage window, do the following:

• If you do not want to use a dedicated Node for storing Container backups, select the Use

local Hardware Node radio button, and click OK to set the Source Node as the default

Backup Node.

• If you are going to use a dedicated Node for storing Container backups, select the Choose

Hardware Node from the list below radio button. The table below this radio button lists all

Nodes registered in Parallels Management Console together with their IP addresses. If the default Backup Node already exists for the given Source Node, it is selected in the table. Select the Node you want to be the default Backup Node for the Source Node, and click OK.

4 Click OK.

The assignment of the default Backup Node brings about the following effects:

• When backing up Containers from the corresponding Source Node in Parallels Management Console and Parallels Virtual Automation using the 'default' backup mode, the backups are automatically placed onto the default Backup Node.

• When backing up Containers form the corresponding Source Node in Parallels Management Console and Parallels Virtual Automation using the 'custom' backup mode, you are automatically offered to place the backups onto the default Backup Node.

• When a Container administrator backs up his or her Container using Parallels Power Panel, the backup is automatically placed on the default Backup Node.

There are no restrictions as to which Hardware Node can be the default Backup Node. It just must be registered in Parallels Management Console (otherwise, it will not be displayed in the table on the Backup Storage screen) and have sufficient disk space for housing multiple backups.

Note: You can use any Hardware Node as a Backup Node irrespective of a Parallels Virtuozzo Containers version installed on this Node. So, you can back up a Container from the Node running the Parallels Virtuozzo Containers 32-bit version and store it on the Node running the Parallels Virtuozzo Containers 64-bit version, and vice versa.

Operations on Containers

Setting the Default Backup Location

Parallels Management Console allows you to change the location on the Backup Node where Container backups are stored. By default, the /vz/backup directory is used. To set another backup directory as the default one, right-click the Hardware Node in the left pane of the Parallels Management Console main window, and choose Backup > Set Default Backup Location. The Default Backup Location window appears.

In this window, do the following:

• Select the Back up to local Hardware Node radio button, and specify a backup directory on one of the Backup Node local disk drives. To set a new backup directory, type its full path on the Node in the Path field or click the ... button and select the desired directory in the displayed window.

• Select the Back up to network share radio button to specify a backup directory on a network share—that is, on a Backup Node network drive. To do this, enter the full path to the directory in the Path field (for example, \\share\backup_directory). If the network drive where the backup directory is located is password-protected, you need to additionally specify the user name and password to access this share in the User and Password fields, respectively.

Once you specify the path to a new directory for storing Container backups, click OK for the changes to take effect.

Note: While defining the default backup directory, make sure that the disk drive where this directory will be located has sufficient disk space for storing multiple Container backups.

Operations on Containers

Defining the Default Backup Compression Level

Parallels Virtuozzo Containers allows you to configure the default backup compression level by setting it to one of the following:

• None. In this case, the Container backup is created without any compression. Using this level of compression, you can greatly reduce the backup creation time. However, the size of the resulting backup file may significantly increase as compared to other compression levels.

• Normal. In this case, the Container backup is created with a normal level of compression. This compression level is set by default and is suitable for backing up most Container files and directories.

• High. In this case, the Container backup is created with the high level of compression. The size of the resulting backup file is smaller than that of the backup file compressed in the 'normal' and 'none' modes; however, it takes longer to create the backup file.

• Maximum. In this case, the Container backup is created with the maximum level of compression. The size of the resulting backup file is the smallest and the time of the backup creation is the longest.

In general, the optimal data compression level depends on the type of files to be stored in the backup archive. For example, it is advisable to use the 'normal' and 'none' compression types if most of the files to be backed up are already compressed (e.g., the files with the .zip and .rar extensions) or can be compressed with a low degree of efficiency (for example, all executable files with the .exe extension or image files with the .jpg, .jpeg., and .gif extensions).

To configure the default backup compression level, do the following:

1 Right-click the respective Source Node, and choose Backup > Set Default Backup Options.

Operations on Containers

2 Under the Compression Level group in the displayed window, move the slider to the left or to

the right to specify the desired compression level.

3 Click OK.

Operations on Containers

Specifying the Default Backup Type

Another parameter that you may wish to configure and that will be applied to all Container backups created using the default backup mode is the backup type. Each backup file can be of one of the following types:

• A full backup containing the whole Container private area and its configuration file.

• An incremental backup containing only the files changed since the full backup or the previous

incremental backup. An incremental backup may prove very useful because it records only the changes since the last Container backup (either full or incremental) and therefore is much less in size and takes much less time than the full backup. However, after several consecutive incremental backups it is recommended to create a full backup anew and start the incremental backups chain from scratch.

• A differential backup containing only the files changed since the last full backup. As a rule, this kind of backup requires less space than a full backup, but more space than an incremental backup.

You can configure the default backup type by doing the following:

1 Right-click the respective Source Node, and choose Backup > Default Backup Node

Configuration:

Operations on Containers

2 Under the Backup Type group in the displayed window, choose one of the following options:

• Select the Full radio button to always create full backup archives containing the whole

Container private area, all Container-related configuration files, action scripts, etc.

• Select the Incremental or Differential radio button to always perform incremental or

differential backups, respectively. If an incremental or differential backup is performed, and the corresponding full backup cannot be found, a full backup is automatically performed.

3 Click OK.

Backing Up a Single Container

To back up a single Container on the Source Node, do the following:

1 In Parallels Management Console, click the Parallels Virtuozzo Containers item under the

corresponding Source Node to open the Container manager window.

2 Right-click the Container you want to back up, and choose Backup > Back Up Container.

The Back Up Containers wizard opens.

Operations on Containers

3 In the first step of the wizard, choose the Container backup mode:

• Default: select this radio button to back up the Container using the default backup mode.

When run in this mode, the default backup parameters are used for creating the Container backup. You can only set the backup description and configure the default backup policy.

Note: Detailed information on what default backup parameters are and how to manage them is given in Setting the Default Backup Parameters (p. 66).

• Custom: select this radio button to manually set the parameters to be applied to the

resulting backup archive. In this case you will have to go through a number of steps (Steps 4 and 5) of the Back Up Containers wizard and set all the parameters of the Container backup one by one.

4 In the second step of the wizard, specify the files and directories to be included in the backup:

Operations on Containers

By default, all Container files and directories are included in the backup archive. To leave out a file or directory from the backup process, clear its check box in the Included files table. You can also select the Matching the following criteria check box and use the Add/Edit/Remove buttons to set the parameters to be met by the file/directory to exclude it from the backup process. You can specify the full path to the corresponding file/directory, enter its name, or define any filter compatible with standard Linux masking rules (i.e. with standard globs). For example, you can indicate /usr/MyDirectory/MyFile.txt to exclude the MyFile.txt

file from the backup process or type *.bmp to leave out all files with the bmp extension.

5 Next, specify the main backup parameters.

Operations on Containers

In this window, you can configure the following backup parameters:

• Choose the Backup Node where the backup is to be stored. You can leave the Backup

Node offered by Parallels Management Console by default or use the Change button to specify another Backup Node. For detailed information on Backup Nodes, see Assigning the Default Backup Node (p. 66).

• Decide on the backup compression level: 'None', 'Normal', 'High', or 'Maximum'. Detailed

information on compression levels is given in Defining the Default Compression Level (p.

69).

• Specify the backup type. It can be full, incremental, or differential. Detailed information on

backup types is provided in Specifying the Default Backup Type (p. 71). If you are backing up a single Container, and no backup of this Container has been found on the Backup Node, the Backup Type group is not shown, and a full backup is automatically created.

6 In the next step of the wizard, you can set the following backup parameters:

• Provide the backup description in the Backup description field, if necessary. The

description can be any text containing any backup-related information (for example, the backup purpose).

• Do not stop the Container backup even if any errors appear (select the Do not stop on

errors check box) or break the backup process if any malfunction occurs (clear the check

box).

• Do not stop the backup process if one or more of the Containers to be backed up do not

exist on the Source Node (select the Ignore non-existent Containers check box) or break the backup process in this case (clear the check box). You can use this option when backing up several Containers at once.

7 The last screen allows you to review the information provided by you in the previous steps of

the wizard. Click Finish to start creating the Container backup; otherwise, click Back to return to any step and correct the corresponding parameter.

Operations on Containers

Backing Up Groups of Containers

To back up several or all Containers from a Source Node, right-click the Parallels Virtuozzo Containers item under the corresponding Source Node, and choose Backup > Back up Containers. The Back Up Containers wizard opens. In this wizard, do the following:

1 Choose the Containers from the Source Node to back up.

Operations on Containers

To schedule one or more Containers for backing up, click the Add button in the top left corner, and in the displayed window, select the names of the Containers to back up, and click OK. The selected Containers will be shown in the table in the center of the Choose Containers to Back Up screen. Click Next to proceed with the wizard.

2 Choose the Container backup mode:

• Default: select this radio button to back up the Container using the default backup mode.

When run in this mode, the default backup parameters are used for creating the Container backup. You can only set the backup description and configure the default backup policy.

Note: Detailed information on what default backup parameters are and how to manage them is given in Setting Default Backup Parameters (p. 66).

• Custom: select this radio button to manually set the parameters for the resulting backup

archive. In this case, you will have to go through a number of steps (Steps 3 and 4) of the Back Up Containers wizard and set all the required backup parameters one by one.

3 Specify the files and directories to include in the backup.

Operations on Containers

By default, all Container files and directories are included in the backup archive. However, you can select the Matching the following criteria check box and use the Add/Edit/Remove buttons to set the parameters to be met by the file/directory to exclude it from the backup process. You can specify the full path to the corresponding file/directory, enter its name, or define any filter compatible with standard Linux masking rules (i.e. with standard globs). For example, you can indicate /usr/MyDirectory/MyFile.txt to exclude the MyFile.txt file from the backup process or type *.bmp to leave out all files with the bmp extension.

4 Next, specify the main backup parameters.

Operations on Containers

In this window, you can configure the following backup parameters:

• Backup Node. This Node is the place where the Container backup will be stored. You can

leave the Backup Node offered by Parallels Management Console by default or use the Change button to specify the desired Backup Node. For detailed information on Backup Nodes, see Assigning the Default Backup Node (p. 66).

• Backup compression level: 'None', 'Normal', 'High', or 'Maximum'. Detailed information on

compression levels is provided in Defining the Default Compression Level (p. 69).

• Backup type. It can be full, incremental, or differential. Detailed information on backup types

is provided in the Specifying the Default Backup Type subsection (p. 71).

5 In the next step of the wizard, you can set the following backup parameters:

• Provide the backup description in the Backup description field, if necessary. The

description can be any text containing any backup-related information (for example, the backup purpose).

• Do not stop the Container backup even if any errors appear (select the Do not stop on

errors check box) or break the backup process if any malfunction occurs (clear the check

box).

• Do not stop the backup process if one or more of the Containers to be backed up do not

exist on the Source Node (select the Ignore non-existent Containers check box) or break the backup process in this case (clear the check box).

6 Review the information provided by you in the previous steps of the wizard. Click Finish to start

creating the Container backup or click Back to return to any step and correct the corresponding parameters.

Another way of backing up a number of Containers from the given Source Node is the following:

1 Expand the Source Node item in the left pane of the Parallels Management Console main

window, and click the Parallels Virtuozzo Containers item to open the Containers manager window.

2 Select the Containers you want to back up. Use the CTRL and SHIFT keys for selecting a

number of Containers.

3 Right-click the selection, choose Back up Containers.

The aforementioned Back Up Containers wizard is opened directly at the second page because the first page (Choose Containers to Back Up) becomes unnecessary.

Operations on Containers

Browsing the Backup Contents

Parallels Management Console allows you to browse the directory structure of any Container backup as if this backup had already been restored and restore only the needed files and directories, if necessary. To view the backed up files and directories of a Container backup, do the following:

1 Choose the Backups item in the Parallels Management Console right pane, right-click the

Container backup whose contents you want to browse, and choose Properties.

2 In the displayed window, select the corresponding backup in the Available backups table, and

click the Show Backup Contents button at the bottom of the window.

Operations on Containers

3 Double-click the directory to see its contents. The information on any file/directory inside the

backup is shown in the table having the following columns:

Column Name Description

Title The name of the file/directory.

Type Denotes whether the object is a file, directory, or Parallels Virtuozzo Containers file link

(i.e. a link to the corresponding file on the Node).

Size The size of the file.

Modified The date and time when the file/directory was modified last time.

If you wish to restore any files and/or directories from the backup to the actual Container, select the check boxes near the corresponding files/directories and click the Restore Selected Items button. Detailed information on how to restore individual files/directories is provided in the Restoring Container Files subsection.

Operations on Containers

Restoring a Single Container

To restore a Container from its backup, do the following:

1 Expand the Source Node item in the left pane of the Parallels Management Console main

window, and click the Parallels Containers item to open the Containers manager window.

2 Select the Container whose backup you want to restore from the Backup Node.

3 Click the right mouse button, and choose Backup > Restore Container.

The Restore Container wizard opens.

Operations on Containers

In this wizard, do the following:

• In the Choose Backup Node and Backup Archive window:

• Select the Backup Node. This Node is the place where the Container backup is stored. The

Last Backup Date column in the list of Backup Nodes shows the date and time of the last backup (if any) of the selected Container on the corresponding Node.

• Select the backup from which to restore the Container. A Container can have a number of

backups made at different dates and of different types. As a rule, you choose the most recent backup, unless you have reasons to restore an intermediary one.

• In the Review Container Restoration Settings window:

• Review the parameters provided by you in the previous step of the wizard.

• Click the Finish button to start restoring the Container.

Note: During this operation, the Destination Node is supposed to be the same as the Source Node. For instructions on how to restore a Container to a Destination Node other than the Source Node, see Managing the Backup Node.

Operations on Containers

Restoring Container Files

Parallels Virtuozzo Containers allows you to browse the directory structure of any Container backup as if this backup had already been restored and restore only the needed files and folders/directories. To do this:

1 Expand the Source Node item in the left pane of the Parallels Management Console main

window, and click the Parallels Virtuozzo Containers item.

2 Right-click the Container the files/folders of which you want to restore, and choose Backup >

Restore Individual Container Files. The Restore Individual Container Files wizard opens.

Operations on Containers

In the first step of the wizard, do the following:

• Choose the Backup Node. This Node is the place where the Container backup is stored. The Last Backup Date column in the list of Backup Nodes shows the date and time of the last backup (if any) of the selected Container on the corresponding Node.

• Choose the backup from which to restore the Container files/directories. A Container can have a number of backups made at different dates and of different types.

The second step of the wizard allows you to review and explore the contents of all the directories that were present inside the Container at the moment of the backup creation.

Operations on Containers

Double-click the directory to see its contents. The information on any file/directory inside the backup archive is presented in the table having the following columns:

Column Name Description

Title The name of the file/directory.

Type Denotes whether the object is a file, directory, or Parallels Virtuozzo Containers file link

(i.e. a link to the corresponding file on the Node).

Size The size of the file.

Modified The date and time of the last modification of the file/directory.

To enqueue a file/directory for being restored, select its check box. You can restore all the files and subdirectories included in a given directory by selecting the check box next to this directory.

The last step of the wizard allows you to review the parameters provided by you in the previous steps of the wizard. If you are satisfied with the specified parameters, click Finish to start restoring the Container files/directories; otherwise, click Back and change the corresponding parameters.

Note: During this operation, the Destination Node is supposed to be the same as the Source Node. For instructions on how to restore Container files/folders/directories to a Destination Node other than the Source Node, see Managing the Backup Node.

Operations on Containers

Restoring Groups of Containers

To restore several Containers of a single Source Node from their backups on the Backup Node, do the following:

1 Right-click the Parallels Virtuozzo Containers item under the corresponding Source Node,

and choose Backup > Restore Containers. The Restore Containers wizard opens.

2 Choose the Backup Node on the Choose Backup Node screen. This Node is the place where

the backups of the Source Node Containers are stored. The Backup Availability column in the list of Backup Nodes shows whether any backups have been found on the corresponding Node.

3 On the Choose Containers to Restore screen, select the Containers you want to restore from

the Backup Node.

Operations on Containers

By default, all backups of Containers originally belonging to the Source Node are selected. You can exclude certain Containers from this list, as well as include in it any other backups found on this Backup Node—that is, the backups of those Containers not belonging to the Source Node. To include these other backups, you first need to make them visible by selecting the Show all available backups check box.

4 If the Containers to restore exist on the Destination Node, you are presented with the Resolve

Conflicts With Existing Containers window listing these Containers. When deciding on

whether to restore a Container, keep in mind that, during the restore process, all Container current data will be overwritten with data from the corresponding backup.

5 On the Review Containers Restoration Settings screen, click the Finish button to start

restoring the Containers.

Note: During this operation, all the Containers will be restored to the Source Node—that is, to the Node for which you have invoked the wizard, irrespective of whether the backed up Containers originally belonged to this Source Node or to any other Node.

You can also restore groups of Containers using these tools:

• Parallels Virtual Automation. For more information on this web-based tool, see the Parallels Virtual Automation Administrator's Guide at

http://www.parallels.com/products/pva46/resources.

• vzarestore. Detailed information on this command-line utility is provided in the Parallels Virtuozzo Containers 4.7 Reference Guide.

Operations on Containers

Managing the Backup Node

Any Hardware Node can perform the functions of the Backup Node—that is, store the backups of any Containers of any Hardware Nodes. To see the list of Container backups stored on a Hardware Node, expand its name in the left pane of the Parallels Management Console main window, and click the Backups item.

Operations on Containers

The table in the right pane shows the following information about the backups stored on the given Backup Node:

Column Name Description

Name The name of the backed up Container.

Source Node The Node where the Container was hosted during its backing up.

Last Backup Date The date and time when the last backing up of the Container took place.

Number of Backups The number of Container backups on the Node.

Description The backup description.

The backup manager window allows you to perform the following operations:

• Restore a single Container from its backup. To do this, right-click the needed Container backup, and choose Restore Container to start the Restore Container wizard. In this wizard, you need to select the Destination Node—the place whither to restore the Container. By default, the Container Source Node is selected. Only the Nodes registered in Parallels Management Console are shown.

• Restore one or several files and/or directories from a particular Container backup. To do this, right-click the Container backup whose files/directories you want to restore, and choose Restore Individual Container Files to start the Restore Individual Container Files wizard. In this wizard:

1. Select the Destination Node—the place whither to restore the Container files/directories.

Operations on Containers

By default, the Container Source Node is selected. Only the Nodes registered in Parallels Management Console are shown. You can also restore the files to your local computer, i.e. to the computer where Parallels Management Console is installed. To do this, select the Restore to local machine radio button and, in the Path field, specify the path to the folder whither to restore the files.

2. Select the Container files/directories to restore to the Destination Node:

The Choose Files to Restore window lists all files and directories that you have backed up. To enqueue a file/directory for being restored, select its check box. You can select the check box next to the corresponding directory to restore all the files and subdirectories from this directory.

3. In the Review Container Restoration Settings window, you can review the parameters

entered in the previous steps of the wizard. If you are satisfied with the specified parameters, click Finish to start restoring the selected files/directories. Otherwise, click Back, and change the necessary parameters.

Operations on Containers

Right-clicking a Container backup in the backups list and choosing Properties brings about the Container Backups dialog where you can do the following:

• View extensive information about the selected Container backup including all its full, incremental, and differential backups.

• Delete any of the existing backups.

• Explore the backup contents (the Container files and directories)

• Restore the Container or any of its files/directories.

Operations on Containers

Searching for Container Backups

If you do not remember the place where you are storing the backup of a particular Container (identified by its ID or its IP address or its hostname or by the date of its creation), you can search for the backup across all the Hardware Nodes registered in Parallels Management Console.

To search for a backup, do the following:

1 Right-click the Parallels Containers item under the corresponding Backup Node name, and

choose Backup > Search for Backups to open the Find Container Backups dialog:

Operations on Containers

2 On the upper left drop-down menu, choose the Container parameter by which you want to

search for the corresponding Container backup.

3 Enter the value of the parameter in the text field on the right. All the Containers with the

corresponding parameter including the specified value as its part will be found. For example, if you enter "100" as the value for Container ID, the backups of Containers 100, 1000, 1001, 1002, 2100, 3100, and so on, will be searched for.

4 Check those Nodes where you want to search for the backups.

5 Click the Search button.

The Search results table presents the following information about the found backups:

Column Name Description

Name The name of the Container whose backup has been found.

Source Node The Node where the Container was hosted during its backing up.

Date of Creation The date and time when the backup was created.

Type The backup type. Detailed information on all backup types is given in Defining

Default Backup Type (p. 71).

Backup Node The Backup Node - the Node where the backup has been found.

Description The backup description.

Double-clicking on a Container backup in this table brings about the Container Backups dialog where you can view extensive information about the current Container backup, including all its full and incremental backups, as well as delete any of these backups or restore them in the manner depicted above.

Operations on Containers

Scheduling Container Backups

Parallels Management Console allows you to automate the task of backing up Containers by setting backups to be run on a schedule. For example, you can specify specific time intervals for creating Container backups. You can set a Container to be backed up at different intervals: daily, weekly, monthly. You can also specify a particular day of month for a Container backup to be executed.

Parallels Management Console provides you with a special wizard—Schedule Task for Backing Up Containers—that helps schedule the time for backing up Containers. To launch the wizard, right-click the Scheduled Tasks item under the corresponding Hardware Node name, and choose Schedule New Task > Back Up Containers.

In this wizard, do the following:

1 Choose the Containers to be backed up on the schedule you will set in the following steps of

the wizard.To do this, click the Add button in the top right corner of the Choose Containers to Backup Up window, select the names of the corresponding Containers, and click OK. When you are ready, click Next to proceed with the wizard.

2 Choose the Container backup mode:

• Default: select this radio button to back up the Container using the default backup mode.

When run in this mode, the default backup parameters are used for creating the Container backup. You can only set the backup description and configure the default backup policy.

Note: Detailed information on what default backup parameters are and how to manage them is given in Setting Default Backup Parameters (p. 66).

• Custom: select this radio button to manually set the parameters to be applied to the

resulting backup archive. In this case, you will have to go through a number of additional steps (Steps 3 and 4) of the Schedule Backup Task for Container(s) wizard and set the necessary backup parameters one by one.

3 Specify the files and directories to be included in the backup.

Operations on Containers

By default, all Container files and directories are included in the backup archive. To leave out a file or directory from the backup process, clear its check box in the Included files table. You can also select the Matching the following criteria check box and use the Add/Edit/Remove buttons to set the parameters to be met by the file/folder to exclude it from the backup process. You can specify the full path to the corresponding file/folder, enter its name, or define any filter compatible with standard Linux masking rules (i.e. with standard globs). For example, you can indicate /usr/MyDirectory/MyFile.txt to exclude the MyFile.txt file from

the backup process or type *.bmp to leave out all files with the bmp extension.

Note: The Included files table is not shown if you are creating a backup task for several Containers.

4 Next, you should specify the main backup parameters.

Operations on Containers

In this window you can configure the following backup parameters:

• Backup Node. This Node is the place where the Container backup will be stored. You can

• Backup compression level: 'None', 'Normal', 'High', or 'Maximum'. Detailed information on

compression levels is given in Defining the Default Compression Level (p. 69).

• Backup type. It can be full, incremental, or differential. Detailed information on backup types

is provided in Specifying the Default Backup Type (p. 71). If you are backing up a single Container, and no backup of this Container has been found on the Backup Node, the Backup Type group is not shown, and a full backup is automatically created.

5 In the next step of the wizard, you can set the following backup parameters:

• Provide the backup description in the Backup description field, if necessary. The

description can be any text containing any backup-related information (for example, the backup purpose).

• Do not stop the Container backup even if any errors appear (select the Do not stop on

errors check box) or break the backup process if any malfunction occurs (clear the check

box).

• Do not stop the backup process if one or more of the Containers to be backed up do not

exist on the Source Node (select the Ignore non-existent Containers) or break the backup process in this case (clear the check box). You can use this option when backing up several Containers at once.

6 Next, you need specify a number of parameters for the backup task being created.

Operations on Containers

100

Parallels Virtuozzo Containers - 4.7 - Linux User's Guide

Specifications and Main Features

Frequently Asked Questions

User Manual

Introduction

About This Guide

Organization of This Guide

Documentation Conventions

Getting Help

Feedback

Parallels Virtuozzo Containers Philosophy

About Parallels Virtuozzo Containers Software

What is Parallels Virtuozzo Containers

What is Container

Parallels Virtuozzo Containers Applications

Distinctive Features of Parallels Virtuozzo Containers

OS Virtualization

Using Virtuozzo File System

Templates

Resource Management

Main Principles of Parallels Virtuozzo Containers Operation

Basics of Parallels Virtuozzo Containers Technology

Parallels Virtuozzo Containers Configuration

Parallels Virtual Automation Overview

Parallels Power Panel Overview

Parallels Management Console Overview

Hardware Node Availability Considerations

Operations on Containers

Creating Containers

Before You Begin

Choosing a Container ID

Choosing an OS EZ Template

List of Supported Linux Distributions for Containers

Creating a Container

Configuring Containers

Setting Startup Parameters

Setting Network Parameters

Setting the root Password for Containers

Starting, Stopping, Restarting, and Querying the Status of Containers

Listing Containers

Setting Names for Containers

Storing Extended Information on Containers

Migrating Containers

Standard Migration

Zero-Downtime Migration

Migrating Containers Based on Standard Templates

Configuring Non-Root Access for Migrating Containers

Moving Containers Within the Hardware Node

Copying Containers Within the Hardware Node

Backing Up and Restoring Containers

Using vzabackup/vzarestore Utilities

Restoring Containers Based on Standard Templates

Managing Backups in Parallels Management Console

Setting Default Backup Parameters

Assigning the Default Backup Node

Setting the Default Backup Location

Defining the Default Backup Compression Level

Specifying the Default Backup Type

Backing Up a Single Container

Backing Up Groups of Containers

Browsing the Backup Contents

Restoring a Single Container

Restoring Container Files

Restoring Groups of Containers

Managing the Backup Node

Searching for Container Backups

Scheduling Container Backups