Hewlett-Packard 2760p Instruction Manual
RAID
User Guide
© Copyright 2011 Hewlett-Packard
Development Company, L.P.
Intel is a trademark of Intel Corporation in
the U.S. and other countries. Microsoft,
Windows, and Windows Vista are U.S.
registered trademarks of Microsoft
Corporation.
The information contained herein is subject
to change without notice. The only
warranties for HP products and services are
set forth in the express warranty statements
accompanying such products and services.
Nothing herein should be construed as
constituting an additional warranty. HP shall
not be liable for technical or editorial errors
or omissions contained herein.
First Edition: May 2011
Document Part Number: 651196-001
Product notice
This user guide describes features that are
common to most models. Some features
may not be available on your computer.
Table of contents
1 Introduction ..................................................................................................................................................... 1
2 RAID technology overview ............................................................................................................................. 2
RAID terminology ................................................................................................................................. 2
RAID modes supported ........................................................................................................................ 3
The advantages of RAID modes supported ......................................................................................... 6
3 Operating systems and devices supported ................................................................................................. 7
Operating systems supported .............................................................................................................. 7
Devices supported ................................................................................................................................ 7
4 Intel Rapid Storage Technology features ................................................................................................... 10
Advanced Host Controller Interface ................................................................................................... 10
Intel Rapid Recover Technology ........................................................................................................ 11
5 RAID volume setup ....................................................................................................................................... 12
Enable RAID through the system BIOS (f10) ..................................................................................... 13
Initiate RAID migration using Intel Rapid Storage Technology Console ............................................ 15
Using Intel Rapid Storage Technology Console Recovery features .................................................. 34
6 Resetting RAID drives to non-RAID ............................................................................................................ 37
7 Frequently asked questions ........................................................................................................................ 39
Can more than one RAID volume be installed on a computer? ......................................................... 39
Is RAID supported to allow both RAID 0 and RAID 1 on a single RAID volume? .............................. 39
Can the computer be undocked if the recovery HDD is in the docking station SATA-swappable
bay? .................................................................................................................................................... 39
What are the maximum number of HDDs that can be connected to the system during boot when
the storage controller is in RAID mode (f10 Computer Setup)? ......................................................... 39
Index ................................................................................................................................................................... 40
iii
iv
1Introduction
Until recently, there were limited options for most computer users who wanted to protect their data
from loss in the event of a hard drive failure. These options were manually copying files to a backup
drive or using cumbersome backup software. If users failed to perform one of these mundane tasks
prior to a hard drive failure, they had to spend considerable time and money to recover even a portion
of the data on the drive. Server and desktop computer users have long enjoyed the security and
benefits of RAID (Redundant Array of Independent Disks) technology to recover data in the event of
drive failure.
HP now offers a simple RAID solution for notebook computer users who need to protect data on a
Serial ATA (SATA) disk drive in case of drive failure or virus attacks. HP’s RAID solution also benefits
computer users who frequently work with large files and want to improve the storage performance of
their computer.
NOTE: The illustrations in this guide are provided in English only.
1
2 RAID technology overview
This chapter defines the terms used in this guide and describes the RAID technologies supported by
select HP Business computers.
RAID terminology
Some of the terms in the following table have a broader meaning, but they are defined in relation to
the RAID implementation described in this guide.
Term Definition
Fault tolerance The ability of the computer to continue to operate if one drive fails. Fault tolerance is
HDD One physical hard disk drive in the RAID array.
Option ROM A software module inside the system's BIOS that provides extended support for a
Primary drive The main internal HDD in the computer.
RAID array The physical drives that appear as one logical drive to the operating system.
RAID migration The change of data from a non-RAID to RAID configuration. “RAID level migration,” or
RAID volume A fixed amount of space across a RAID array that appears as a single HDD to the
Recovery drive The hard drive that is the designated mirror (copy of the primary) drive in a RAID 1 and
Reliability The likelihood—over a period of time—that a HDD can be expected to operate without
Stripe The set of data on a single hard drive in a RAID volume.
Striping The distribution of data over multiple disk drives to improve read/write performance.
often used interchangeably with reliability, but the two terms are different.
particular piece of hardware. The RAID option ROM provides boot support for RAID
volumes as well as a user interface for managing and configuring the system's RAID
volumes.
the change of data from one RAID level to another, is not supported.
operating system.
Recovery volume.
failure, also known as mean time before failure (MTBF).
2 Chapter 2 RAID technology overview
RAID modes supported
The RAID modes supported by HP Business computers include RAID 0, RAID 1, RAID 5, and
Flexible data protection (Recovery) as described below. RAID modes 0, 1, and Recovery require two
SATA HDDs. RAID mode 5 requires three SATA HDDs. This can be accomplished by inserting a
second SATA hard drive into the Upgrade Bay, eSATA port (if available), or the second hard drive
bay (if available) of the computer, or into the SATA-swappable bay of the HP Advanced Docking
Station (see
RAID 0
RAID 0 stripes, or distributes, data across both drives. This allows data, especially large files, to be
read faster because data is read simultaneously from both drives. However, RAID 0 offers no fault
tolerance, which means that if one drive fails, the entire array fails.
The usable amount of the drives is the minimum size of the unassigned space x 2 (number of the
HDDs). For example, if disk 1 has 150 GB of free space and disk 2 has 600 GB of free space, the
usable amount is 150 GB x 2 = 300 GB. It is recommended to use HDDs of the same size and
specifications for RAID configuration.
RAID 1
RAID 1 copies, or mirrors, identical data on two HDDs. If one HDD fails, RAID 1 allows data to be
recovered from the other HDD.
Devices supported on page 7). RAID 10 is not supported.
The usable amount of the drives is the minimum size of the unassigned space. For example, if disk 1
has 150 GB of free space and disk 2 has 600 GB of free space, the usable amount is 150 GB. It is
recommended to use HDDs of the same size and specifications for RAID.
RAID 5
RAID 5 distributes data across three HDDs. If one HDD fails, RAID 5 allows data to be recovered
from the other two HDDs.
The usable amount of the drives is the minimum size of the unassigned space x 3 (number of the
HDDs) x 2/3. For example, if disk 1 has 150 GB of free space, disk 2 has 600 GB of free space, and
disk 3 has 400 GB of free space, the usable amount is 300 GB (150 GB x 3 x 2/3). It is recommended
to use HDDs of the same size and specifications for RAID.
Flexible data protection (Recovery)
Flexible data protection (Recovery) is a feature of Intel® Rapid Storage Technology software.
Recovery enhances RAID 1 functionality with several features that make it easier for users to mirror
data to a designated recovery drive. For example, Recovery allows users to determine how the
recovery volume is updated, either continuously (the default) or on request. Recovery also enables
docking and undocking of the computer if the second drive is in the docking station's bay.
RAID mode summary
The following table describes the functions, applications, and advantages and disadvantages of the
supported RAID modes.
RAID modes supported 3
RAID levels Function/Applications Advantages/Disadvantages
RAID 0
RAID 1
Function:
Data is distributed across
both disk drives.
Applications:
Image editing
●
● Video production
Pre-press applications
●
Function:
Identical (mirrored) data is
stored on two drives.
Applications:
Accounting
●
Payroll
●
Advantages:
Read performance is
higher than that of a nonRAID HDD.
Total storage capacity is
doubled.
Disadvantages:
The entire array fails if one
drive fails; data cannot be
recovered.
Storage space may be
wasted if the capacities of
the primary and recovery
HDDs are different (see
SATA drive option kits
on page 7).
Advantages:
Provides high fault
tolerance.
Disadvantages:
Only half of the total drive
capacity can be used for
storage.
HP
● Financial
Storage space may be
wasted if the capacities of
the primary and recovery
HDDs are different (see
SATA drive option kits
on page 7).
HP
4 Chapter 2 RAID technology overview
RAID levels Function/Applications Advantages/Disadvantages
RAID Recovery
Function:
Identical (mirrored) data is
stored on two drives.
Boosts the functionality of
RAID 1 with valuable
features.
Applications:
Any application that requires
a simple data protection
method.
Advantages:
Provides high fault
tolerance.
Users can choose to mirror
data continuously or on
request.
Data recovery is quick and
easy.
Allows hot-plugging of
mirrored drive (with eSATA
or docking station HDD).
Enables easy migration to
non-RAID.
Disadvantages:
Only half of the total drive
capacity can be used for
storage.
Storage space may be
wasted if the capacities of
the primary and recovery
HDDs are different.
RAID 5
Function:
Distributes data across three
HDDs. If one HDD fails,
RAID 5 allows data to be
recovered from the other two
HDDs.
Applications:
A good choice for large
amounts of critical data.
Advantages:
Data redundancy
Improved performance and
capacity
High fault-tolerance and
read performance
Disadvantages:
During a RAID rebuild after a
hard drive fails, system
performance can be
decreased.
RAID modes supported 5
The advantages of RAID modes supported
Fault tolerance and performance are important terms to understand when choosing a RAID mode.
Fault tolerance
Fault tolerance is the ability of a RAID array to withstand and recover from a drive failure. Fault
tolerance is provided by redundancy. Therefore, RAID 0 has no fault tolerance because it does not
copy data to another HDD. With RAID 1 and Recovery, one drive can fail without causing the array to
fail. With Recovery, however, the restoration of a single file or an entire HDD is much simpler than
with RAID 1 alone. With RAID 5, one of the three HDDs can fail without causing the array to fail.
Performance
Performance is easy to understand, but it is difficult to measure because it involves several factors,
some of which are beyond the scope of this document. Overall storage performance is determined by
write performance and read performance, both of which vary based on the RAID technology selected.
RAID 0 (striping) improves overall storage performance because data can be written and read
●
simultaneously across two HDDs.
Recovery and RAID 1 (mirroring) writes the same data to both HDDs; therefore, write
●
performance may be slower. However, data can be read from both HDDs, so the read
performance can be higher than that of a single non-RAID HDD.
● RAID 5 performs at a level between RAID 0 and RAID 1.
6 Chapter 2 RAID technology overview
3 Operating systems and devices
supported
Operating systems supported
HP RAID supports 32-bit and 64-bit versions of Windows Vista® (SP1 and SP2), and Windows 7
operating systems.
NOTE: HP offers only limited support for Microsoft® Windows® XP Professional (SP1, SP2,and
SP3).
Devices supported
This section describes the devices supported for RAID migration, including the SATA drives,
computers, and docking station. Device support is summarized in the following table and then
explained in more detail below the table. External USB SATA drives connected to the computer or
docking station cannot be used for migrating to RAID.
Primary and Upgrade Bay
SATA HDDs in the
computer
RAID 0 Yes Yes No
RAID 1 Yes Yes No
Recovery Yes Yes Yes
RAID 5 Yes Yes No
HP SATA drive option kits
HP offers SATA drive option kits for the computer Upgrade Bay and the docking station's SATA
swappable bay to support RAID migration. For optimal RAID performance, it is recommended that
both drives have the same speed. However, supported HP Business computers allow drives with
different speeds to be used in a RAID volume.
Drives of different capacities are also supported for RAID migration, as long as the capacity of the
secondary (recovery) drive is equal to or greater than that of the primary drive. For example, if the
primary drive is 200 GB, then at least a 200-GB drive is required in the Upgrade Bay to create a RAID
volume. If the capacity of the secondary drive is larger than that of the primary drive, the excess
capacity of the secondary (or third) drive will not be accessible. If, for example, the primary drive is
160 GB and the secondary drive is 250 GB, only 160 GB of the secondary drive will be usable in a
Primary and secondary
bay SATA HDDs in the
computer
Docking station HDD or
eSATA HDD attached to
computer
Operating systems supported 7
RAID configuration. Therefore, for optimal use, it is recommended that both drives have the same
capacity.
eSATA HDDs (select models only)
External SATA, or eSATA, is an external interface that allows a SATA drive to achieve data transfer
speeds up to 6 times that of a SATA drive using a standard USB 2.0 interface. The following
illustration shows a supported computer with a primary HDD (1) and an eSATA drive (2) connected to
the eSATA port (select models only) to allow Recovery. Regarding the capacity of the eSATA drive,
the same recommendations apply as stated for secondary drives in the computer Upgrade Bay.
HP Business computers
Select HP Business computers support RAID using Intel® Rapid Storage Technology software (v10
and higher) and a second SATA drive in the Upgrade Bay.
The following illustration shows a supported computer with the primary HDD (1) and a secondary
HDD drive in the Upgrade Bay (2) that allows RAID 0, RAID 1, and Recovery.
8 Chapter 3 Operating systems and devices supported
The following illustration shows a supported computer with the primary HDD (1) and secondary HDD
(2), with the third drive in the Upgrade Bay (3) that allows RAID 5.
HP Advanced Docking Station
Recovery supports docking and undocking. It can be used to implement mirroring between the
primary HDD (1) and an optional HDD in the SATA-swappable bay of the HP Advanced Docking
station (2).
The following illustration shows an HP Advanced Docking Station with the recovery HDD in the
SATA-swappable bay that allows Recovery.
Devices supported 9
4 Intel Rapid Storage Technology
features
Intel Rapid Storage Technology supports the following Recovery features.
Advanced Host Controller Interface
The Advanced Host Controller Interface (AHCI) is a specification that allows the storage driver to
enable advanced SATA features such as Native Command Queuing and hot plug capability. AHCI
must be enabled in the system BIOS for these features to apply (see
system BIOS (f10) on page 13). AHCI is enabled by default on supported HP Business computers.
Native Command Queuing
Enable RAID through the
A read/write drive head writes data to an HDD platter in concentric circles (tracks) based on the order
in which the write request was received. Because applications rarely request data in the same order
that it was written to the platter, long delays (latency) would result if the drive head had to locate data
in the exact order that the HDD receives read requests. Native Command Queuing (NCQ) allows
SATA HDDs to accept multiple commands and change their execution order to improve performance.
This is analogous to the way an elevator reorders floor requests to minimize travel time and
mechanical wear. Similarly, NCQ reduces the latency and unnecessary drive head movement
required to execute multiple outstanding read/write requests, resulting in increased performance and
reliability. NCQ requires support from the system BIOS, SATA controller, and controller driver.
Hot plug capability
Hot plug capability allows the SATA recovery HDD to be removed or inserted while the computer is
running. Hot plug capability is supported when the recovery HDD is connected to the eSATA port or
located in the docking station's SATA-swappable bay. For example, the recovery HDD in the docking
station's SATA-swappable bay can be removed while the computer is running if you need to
temporarily insert an optical drive in the bay. Hot plug capability also allows you to dock and undock
the computer at any time.
10 Chapter 4 Intel Rapid Storage Technology features
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