Dell AMP01 User Manual
Dell™ PowerVault™
MD3000i RAID Enclosure
Hardware Owner’s Manual
Notes, Notices, and Cautions
NOTE: A NOTE indicates important information that helps you make better use of
your computer.
NOTICE: A NOTICE indicates either potential damage to hardware or loss of data
and tells you how to avoid the problem.
CAUTION: A CAUTION indicates a potential for property damage, personal injury,
or death.
____________________
Information in this document is subject to change without notice.
© 2007 Dell Inc. All rights reserved.
Reproduction in any manner whatsoever without the written permission of Dell Inc. is strictly
forbidden.
Trademarks used in this text: Dell, the DELL logo, PowerEdge, and PowerVault are trademarks of
Dell Inc.; Microsoft, Windows, Windows Server, and MS-DOS are either trademarks or registered
trademarks of Microsoft Corporation in the United States and/or other countries; UNIX is a registered
trademark of The Open Group in the United States and other countries.
Other trademarks and trade names may be used in this document to refer to either the entities claiming
the marks and names or their products. Dell Inc. disclaims any proprietary interest in trademarks and
trade names other than its own.
Model AMP01
June 2007 Rev. A00
Contents
1 About Your System . . . . . . . . . . . . . . . . . . 9
Overview . . . . . . . . . . . . . . . . . . . . . . . . . 9
Other Information You May Need . . . . . . . . . . . . 11
Enclosure Features
. . . . . . . . . . . . . . . . . . 9
Modular Disk Storage Manager
. . . . . . . . . . 11
Connection Components
About the Enclosure Connections
Hardware Features
Indicators on the Enclosure Bezel
Front-Panel Indicators and Features
Back-Panel Indicators and Features
RAID Controller Modules
Cache Functions and Features
Power Supply and Cooling Fan Features
. . . . . . . . . . . . . . . . 12
. . . . . . . . . . . 12
. . . . . . . . . . . . . . . . . . . 13
. . . . . . . . . 13
. . . . . . . 14
. . . . . . . 18
. . . . . . . . . . . . . 18
. . . . . . . . . . . 24
. . . . . 24
2 Using Your RAID Enclosure . . . . . . . . . . . 27
Physical Disks, Virtual Disks, and Disk Groups . . . . 27
Physical Disks
Physical Disk States
Self-Monitoring Analysis and Reporting
Technology (SMART)
Virtual Disks and Disk Groups
. . . . . . . . . . . . . . . . . . . 28
. . . . . . . . . . . . . . . . 28
. . . . . . . . . . . . . . . . 29
. . . . . . . . . . . 30
Contents 3
Supported RAID Levels . . . . . . . . . . . . . . . . . 31
. . . . . . . . . . . . . . . . . . . . . . . 31
RAID 0
. . . . . . . . . . . . . . . . . . . . . . . 31
RAID 1
. . . . . . . . . . . . . . . . . . . . . . . 32
RAID 5
RAID 10
RAID Level Usage
Segment Size
. . . . . . . . . . . . . . . . . . . . . . . 32
. . . . . . . . . . . . . . . . . 32
. . . . . . . . . . . . . . . . . . . . 33
Hot Spares and Rebuild
Global Hot Spares
Hot Spare Operation
. . . . . . . . . . . . . . . . . . . . . . . 34
Rebuild
. . . . . . . . . . . . . . . . . 33
. . . . . . . . . . . . . . . . . 33
. . . . . . . . . . . . . . . . 33
Media Errors and Unreadable Sectors . . . . . . . . . 34
RAID Operations and Features
Virtual Disk Operations
Disk Group Operations
RAID Background Operations Priority
Virtual Disk Migration and Disk Roaming
Advanced Features
. . . . . . . . . . . . . . . . . . . 42
Storage Partitions
Host Types
. . . . . . . . . . . . . . . . . . . . . 44
Snapshot Virtual Disks
Snapshot Repository Virtual Disk
Virtual Disk Service
Volume Shadow-Copy Service
Virtual Disk Copy
Using Snapshot and Disk Copy Together
. . . . . . . . . . . . . 35
. . . . . . . . . . . . . . . 35
. . . . . . . . . . . . . . . 37
. . . . . . . 39
. . . . . 40
. . . . . . . . . . . . . . . . . 42
. . . . . . . . . . . . . . . 44
. . . . . . . . . 45
. . . . . . . . . . . . . . . . . 46
. . . . . . . . . . . 46
. . . . . . . . . . . . . . . . . . 47
. . . . . . 48
4 Contents
Hardware Redundancy and Failover
Redundancy and Non-Redundancy
Multi-Path Software
. . . . . . . . . . . . . . . . 49
. . . . . . . . . . 48
. . . . . . . . 49
When a RAID Controller Module Is Replaced
or Removed
RAID Controller Failover Modes
. . . . . . . . . . . . . . . . . . . . . 50
. . . . . . . . . . 51
Thermal Shutdown
Updating Enclosure Firmware
RAID Controller Module Firmware
Physical Disk Firmware
Expansion Enclosure Firmware
Best Practices and Recommendations
. . . . . . . . . . . . . . . . . . . 52
. . . . . . . . . . . . . 52
. . . . . . . . . 52
. . . . . . . . . . . . . . 53
. . . . . . . . . . 53
. . . . . . . . . 54
3 Installing Enclosure Components . . . . . . 55
Recommended Tools . . . . . . . . . . . . . . . . . . 55
Removing and Replacing the Front Bezel
Removing and Installing Physical Disks
Removing Physical Disks from the Enclosure
Installing SAS Physical Disks in the
Enclosure
. . . . . . . . . . . . . . . . . . . . . . 58
Removing and Installing a RAID Controller
Module
. . . . . . . . . . . . . . . . . . . . . . . . . . 60
Removing a RAID Controller Module
Installing a RAID Controller Module
. . . . . . . . 55
. . . . . . . . 56
. . . 57
. . . . . . . 60
. . . . . . . . 61
Removing and Installing a RAID Controller
Module Backup Battery Unit
. . . . . . . . . . . . . . 62
Removing and Installing the Power Supply/Cooling
Fan Module
. . . . . . . . . . . . . . . . . . . . . . . 64
Removing a Power Supply/Cooling
Fan Module
. . . . . . . . . . . . . . . . . . . . . 64
Installing a Power Supply/Cooling
Fan Module
. . . . . . . . . . . . . . . . . . . . . 65
Contents 5
Removing and Installing the Control Panel . . . . . . . 66
Removing the Control Panel
Installing the Control Panel
. . . . . . . . . . . . 66
. . . . . . . . . . . . 67
Removing and Installing the Midplane
. . . . . . . . . 68
4 Troubleshooting Your Enclosure . . . . . . . 71
Safety First—For You and Your Enclosure . . . . . . . 71
Start-Up Routine
Troubleshooting External Connections
Troubleshooting a Wet Enclosure
Troubleshooting a Damaged Enclosure
Troubleshooting Power Supplies
Troubleshooting Enclosure Cooling Problems
Troubleshooting a Fan
Troubleshooting SAS Physical Disks
Troubleshooting Enclosure Connections
Hard Controller Failures and Lockdown
Conditions
Invalid Enclosure
ECC Errors
PCI Errors
Critical Conditions
Noncritical Conditions
. . . . . . . . . . . . . . . . . . . . . 71
. . . . . . . . . 72
. . . . . . . . . . . . 72
. . . . . . . . . 73
. . . . . . . . . . . . 73
. . . . . 75
. . . . . . . . . . . . . . . 75
. . . . . . . . . . 76
. . . . . . . . 77
. . . . . . . . . . . . . . . . . . . . . . . . 78
. . . . . . . . . . . . . . . . . . 78
. . . . . . . . . . . . . . . . . . . . . 78
. . . . . . . . . . . . . . . . . . . . . . 79
. . . . . . . . . . . . . . . . . 79
. . . . . . . . . . . . . . . 79
6 Contents
5 Getting Help . . . . . . . . . . . . . . . . . . . . . . 81
Obtaining Assistance . . . . . . . . . . . . . . . . . . 81
Technical Support and Customer Service
Online Services
. . . . . . . . . . . . . . . . . . 82
Automated Order-Status Service
. . . . . 82
. . . . . . . . . 83
Dell Enterprise Training
Problems With Your Order
Product Information
Returning Items for Warranty Repair or Credit
Before You Call
Contacting Dell
. . . . . . . . . . . . . . . . . 83
. . . . . . . . . . . . . . . 83
. . . . . . . . . . . . . . . . . . . 83
. . . . . 83
. . . . . . . . . . . . . . . . . . . . . 84
. . . . . . . . . . . . . . . . . . . . . 84
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Contents 7
8 Contents
About Your System
The Dell™ PowerVault™ MD3000i is a 3U rack-mounted external Redundant
Array of Independent Disks (RAID) storage array capable of accommodating
up to 15 3.0-Gbps, Serial-Attached SCSI (SAS) disks. The RAID enclosure
can be daisy-chained with up to two additional MD1000 expansion
enclosures, providing access to a maximum of 45 disks in the entire storage
array. Connectivity between the RAID enclosure and the host server is
provided by a standard Ethernet connection, and communication between
the two is established through an iSCSI initiator.
Overview
The RAID enclosure is designed for high availability, offering redundant
access to data storage. It features support for both single RAID controller
configuration and dual RAID controller configuration. For each
configuration, up to 16 hosts can be connected through industry-standard
1-Gb network interface cards (NICs).
The MD3000i storage array provides dual active/active RAID controller
modules, redundant power supplies, and redundant fans. The RAID
enclosure is designed for high-performance environments: eight-node clusters
or multi-host storage access for up to 16 host servers.
Storage management can be either in-band through the iSCSI connection, or
out-of-band using an Ethernet connection to the Management Port on the
RAID controller modules.
Enclosure Features
Features include:
• Support for up to 16 Microsoft Windows® or Linux host servers
• 3U chassis for rack mounting
• RAID controller modules in two supported configurations:
– Single-controller configurations
– Dual-controller configurations for high availability
About Your System 9
• Two redundant, hot-pluggable power supply/fan modules
• 512 MB of mirrored cache on each RAID controller module
• Battery backup unit in each RAID controller module that protects against
cache data loss for up to 72 hours
• Support for up to 45 3.5" SAS physical disks
• Support for up to 255 virtual disks per disk group
• Up to 2 TB (2036 GB) storage on a single virtual disk
• Support for up to two PowerVault MD1000 expansion enclosures through
SAS Out port connectors on the RAID controller modules
• Online firmware updates (without taking the enclosure offline) for the
following components:
– RAID controller modules
–NVSRAM
– Physical disk
NOTE: Dell recommends stopping all I/O to the array when downloading
physical disk firmware.
– Expansion enclosure management modules (EMMs)
• Task-based configuration software (MD Storage Manager)
• Optional snapshot virtual disk (premium feature), up to four snapshots per
virtual disk and 128 snapshots per array
• Optional virtual disk copy (premium feature), up to 255 virtual disk copies
per array
• Continuous background event monitoring for critical problems, such as
impending physical disk failure or failed RAID controller modules
• Host-based, multipath failover software for redundant configurations to
automatically reroute I/O activity from a failed, offline, or removed RAID
controller module to its alternate RAID controller module (or from a failed
iSCSI connection). This capability maintains a data path between the host
server and the
storage array.
10 About Your System
Modular Disk Storage Manager
The Modular Disk (MD) Storage Manager software is a graphic interface with
wizard-guided tools and a task-based management structure designed to
reduce the complexity of installation, configuration, management, and
diagnostic tasks. MD Storage Manager can be used on any host server
attached to the storage array, as well as on storage management stations
connected to the same subnetwork as the RAID enclosure, to create and
manage multiple storage arrays.
NOTE: The MD Storage Manager uses TCP/UDP port 2463 for discovery and
management of the MD3000i storage array.
For more information, see the MD Storage Manager User's Guide.
Other Information You May Need
CAUTION: The Product Information Guide provides important safety and
regulatory information. Warranty information may be included within this
document or as a separate document.
• The
•
•
• The
• The
• The Dell PowerVault MD3000i
• Dell PowerVault MD1000 Documentation is available at
• Dell PowerEdge Cluster Documentation is available at
Rack Installation Guide
with your rack solution describes how to install your
Getting Started With Your System
features, setting up your
Setting Up Your PowerVault MD3000i
and cabling your storage array.
PowerVault MD3000i Installation Guide
configuration instructions for both software and hardware.
PowerVault MD Storage Manager CLI Guide
about using the command line interface (CLI).
configuration and management tools, as well as the full documentation
set.
for users who incorporate MD1000 expansion enclosures.
A link to clustering documentation is also included on the
under
Product Documentation
or
Rack Installation Instructions
provides an overview of
enclosure
, and technical specifications.
provides an overview of setting up
provides installation and
Resource CD
.
provides documentation for
included
enclosure
provides information
into a rack.
enclosure
support.dell.com
support.dell.com
Resource CD
.
About Your System 11
• Updates are sometimes included to describe changes to the
software, and/or documentation.
NOTE: Always check for updates on support.dell.com and read the updates
first because they often supersede information in other documents.
• Release notes or readme files are included to provide last-minute updates
to the
enclosure
material intended for experienced users or technicians.
or documentation or advanced technical reference
enclosure
,
Connection Components
Before connecting your RAID enclosure, ensure that the following are
available:
• The components that shipped with your RAID
– Power cords (2)
– MD3000i Resource CD
– Setting Up Your PowerVault MD3000i
– Rail kit
• Any relevant documentation, including:
– Getting Started With Your System
–
Rack Installation Guide
–
Product Information Guide
warranty information)
– Readme files
• #2 Phillips screwdriver
or
Rack Installation Instructions
(for important safety, regulatory, and
enclosure
, including:
About the Enclosure Connections
The RAID enclosure is connected to a host server via two RAID controller
modules. The RAID controller modules are identified as RAID controller
module 0 and RAID controller module 1 (see Figure 1-4).
Each RAID controller module has two iSCSI In port connectors that provide
connection to the host server. The iSCSI In port connectors are labeled 0
and 1.
12 About Your System
Each MD3000i RAID controller module also contains a SAS Out port
connector. This port allows you the option to connect the RAID enclosure to
an expansion enclosure.
Refer to the
examples of how to configure your storage array.
PowerVault MD3000i Installation Guide
for details and illustrated
Hardware Features
The remainder of this section describes the hardware features available on the
RAID enclosure, including:
• Indicators on the enclosure bezel
• Front-panel and back-panel indicators and features
• Redundant power supply and cooling fan modules
Indicators on the Enclosure Bezel
An optional locking bezel can be installed on the front of the enclosure to
limit access.
Table 1-1 lists conditions indicated by the lights on the bezel.
on installing and removing the bezel, see "Removing and Replacing the Front
Bezel" on page 55.
Figure 1-1. LEDs on the Front Bezel
Figure 1-1 illustrates the indicators and components on the bezel.
For information
1
2
3
About Your System 13
Table 1-1. Front-Bezel Indicators
Item LED Indicator LED Icon Condition
1 Split mode (green) Because this mode is unused in the system,
this LED should always be unlit.
NOTE: This LED comes on if the enclosure
mode switch on the enclosure’s front panel is
in the split mode position before the
enclosure is turned on.
2 Power (green) When lit, at least one power supply is
supplying power to the enclosure.
3 Enclosure status
(blue/amber)
Steady amber: Power is on and enclosure is
in reset state.
Steady blue: Power is on and enclosure
status is OK.
Flashing blue: Enclosure LED is being
blinked by MD Storage Manager.
Flashing amber: Enclosure is in fault state.
Front-Panel Indicators and Features
Figure 1-2 shows the LED indicators and components on the enclosure’s
front panel (optional locking bezel not shown). Table 1-2 lists the conditions
and functions indicated by each.
14 About Your System
Figure 1-2. Front-Panel Features
1
2
3
4
1 enclosure status
LED
4 enclosure mode
switch
Table 1-2. Front-Panel Components
Component Icon Condition
Enclosure status LED
(blue/amber)
2 power LED 3 split mode LED (not
5 physical disks (15)
Steady amber: Power is on and enclosure is in
reset state.
Steady blue: Power is on and enclosure status
is OK.
Flashing blue: Enclosure LED is being blinked
by MD Storage Manager.
Flashing amber: Enclosure is in fault state.
5
used)
About Your System 15
Table 1-2. Front-Panel Components (continued)
Component Icon Condition
Power LED (green) When lit, at least one power supply is
supplying power to the enclosure.
Split mode LED (green) Because this mode is unused in the system, this
LED should always be unlit.
NOTE: This LED comes on if the enclosure mode
switch on the enclosure’s front panel is in the
split mode position before the enclosure is
turned on.
Enclosure mode switch The function of this switch is not applicable to
your MD3000i. However, if additional MD1000
expansion enclosures are daisy chained to your
system, the enclosure mode switch on those
enclosures must be in unified-mode position.
NOTE: This switch must be set prior to turning
on the system. Changing the switch setting after
the system is turned on will have no effect on
enclosure configuration until the system goes
through a complete power cycle.
Physical Disk Carrier LED Indicators
Each physical disk carrier in your enclosure has two LEDs: an activity LED
(green) and a bicolor (green/amber) status LED (see Figure 1-3). The activity
LED flashes whenever the physical disk is accessed. Table 1-3 lists the flash
patterns for the status LED.
16 About Your System
Figure 1-3. Physical Disk Carrier LED Indicators
1
1 activity LED 2 status LED
Table 1-3. Physical Disk Carrier Status LEDs
Status LED Description
Off Physical disk not yet discovered by host server or an
unsupported disk is present
Steady green Physical disk is online
Green flashing (250 milliseconds
[ms])
Green flashing
On 400 ms
Off 100 ms
Amber flashing (125 ms) Physical disk failed
Flashing green, amber, and off Physical disk failure predicted (SMART)
Green 3 seconds, amber
3 seconds, and off 3 seconds
Physical disk is being identified
Physical disk rebuilding
Physical disk rebuild aborted
2
About Your System 17
Back-Panel Indicators and Features
Figure 1-4 shows the back-panel features of the enclosure. A fully populated
enclosure with dual RAID controllers and two power supply/cooling fan
modules is shown. However, a single RAID controller module is supported,
and the enclosure can run temporarily on one power supply/cooling fan
module. For more information, see "Power Supply and Cooling Fan Features"
on page 24.
Figure 1-4. Back-Panel Features
1 2
3
1 RAID controller
module 0
2 RAID controller
module 1
3 power supply/cooling
fan modules (2)
RAID Controller Modules
The RAID controller modules provide high-performance, advanced virtual
disk configuration, and fault-tolerant disk subsystem management. Each
RAID controller module contains 512 MB of cache that is mirrored with the
other controller's cache for high availability and protected by a battery for up
to 72 hours.
18 About Your System
Each RAID controller module provides data path and enclosure management
functions for your enclosure, including:
• Monitoring and controlling enclosure environment elements
(temperature, fans, power supplies, and enclosure LEDs)
• Controlling access to the
• Communicating
enclosure
physical disk
s
attributes and states to the host server
Each RAID controller module has dual iSCSI In ports for host access. The
two iSCSI ports provide redundant host connections and support a high
availability storage environment. Various configurations can be utilized, in
both
single controller
and
dual controller
mode, to connect the storage
enclosure to hosts depending on specific redundancy needs. For example:
•
Single Path Data Configuration
– The single path provides a large
number of nonredundant physical connections to the array through an
industry-standard Gigabit Ethernet Switch.
•
Redundant Dual Path (RDP) Data Configuration
– The RDP allows two
separate physical paths for each client through a Gigabit Ethernet Switch.
In addition, this configuration provides full redundancy through the use of
either redundant disk array controller (RDAC) drivers or multipathing I/O
(MPIO) drivers.
For detailed information on cabling, see the
.
Guide
PowerVault MD3000i Installation
RAID Controller Module Connectors and Features
Figure 1-5 shows a single
of the enclosure.
RAID controller module
RAID controller module
connectors and components shown
include:
• Two iSCSI In port connectors
• Management port Ethernet connector
NOTE: The RAID controller module network configuration can be assigned
using a DHCP server (the default setting). If a DHCP server is not available
(time-out is 10 seconds) then the RAID controller modules uses the static IP
addresses of 192.168.128.101 for controller 0 and 192.168.128.102 for
controller 1.
as it appears from the rear
About Your System 19
• Eleven LEDs (two iSCSI In link speed/activity, two iSCSI In link duplex
mode, two Ethernet link/speed, battery fault, SAS link fault/connectivity,
cache active, controller fault, and controller power)
• One SAS Out port connector
• Debug port
For a description of each component on the front panel of the RAID
controller module, see Table 1-4. For an explanation of how to connect the
enclosure using the
MD3000i Installation Guide
Figure 1-5. RAID Controller Module External Panel (front view)
1 68 9 10 11 13 15 1612 1442 3 5 7
Table 1-4. RAID Controller Module Component Functions
Item Component Icon Function
1 iSCSI In Port 0 Link
Speed/Activity
Status LED
2 iSCSI In Port 0 In-0 Provide host-to-controller iSCSI
3 iSCSI In Port 0 Link
Duplex Mode
RAID controller module
.
Green: Link is operating at 1000 Mbps.
Amber: Link is operating at 100 Mbps.
Off: iSCSI connection is not active.
connection. If LED is solid, there is no
activity on the link. If the LED is blinking,
there is activity on the link.
Green: Full-duplex mode.
Off: Half-duplex mode.
ports, see the
PowerVault
NOTE: Half-duplex mode is supported only if
the link speed is 100Mbps.
20 About Your System
Table 1-4. RAID Controller Module Component Functions (continued)
Item Component Icon Function
4 iSCSI In Port 1 Link
Speed/Activity
Status LED
5 Battery Fault LED
(amber)
6 Cache Active LED
(green)
7 iSCSI In Port 1 In-1 Provide host-to-controller iSCSI
8 iSCSI In Port 1 Link
Duplex Mode
Green: Link is operating at 1000 Mbps.
Amber: Link is operating at 100 Mbps.
Off: iSCSI connection is not active.
Amber: Battery backup unit or battery has
failed or is missing.
Off: Battery backup unit and battery is
operating normally.
Green: On-board controller memory
contains data.
Off: On-board controller memory is empty.
connection. If LED is solid, there is no
activity on the link. If the LED is blinking,
there is activity on the link.
Green: Full-duplex mode.
Off: Half-duplex mode.
NOTE: Half-duplex mode is supported only if
the link speed is 100Mbps.
9 Controller Fault
LED (amber)
Amber: Controller fault detected.
Off: Controller is operating normally.
10 Controller Power
LED (green)
11 Ethernet Link LED
(green)
12 Management Port
Ethernet Connector
Green: Controller power is on.
Off: Controller is not powered.
Green: Ethernet connection is active.
Off: Ethernet connection is not active.
Provide a 10/100 Mbps Ethernet
connection for out-of-band management of
the enclosure.
About Your System 21
Table 1-4. RAID Controller Module Component Functions (continued)
Item Component Icon Function
13 Ethernet Speed
LED (green)
14 Debug Port Dell support only.
Green: Ethernet connection is operating at
100 Mbps.
Off: Ethernet connection is operating at
10 Mbps or is not active.
15 SAS Link Fault
LED
16 SAS Out Port Out Provides SAS connection for cabling to a
The
RAID controller module
connects to the enclosure midplane via the two
Amber: Between 1–3 links are connected.
Green: All four links are connected.
Off: All links are down.
downchain expansion enclosure.
midplane connectors on its internal (rear) panel. The RAID controller
module is shown in Figure 1-6.
Figure 1-6. RAID Controller Module
1
2
1 battery cover 2 midplane connectors (2)
22 About Your System
Battery Backup Unit
Each RAID controller contains a three-cell lithium-ion battery backup unit
(BBU) that powers the controller’s cache memory and preserves the cache
contents in the event of a power outage of up to 72 hours. The RAID
controller firmware performs a test of the BBU at startup and will illuminate
the battery fault LED if the battery is not operating within specified ranges,
or if the battery is missing. The battery begins recharging automatically if the
test determines that it is necessary. For a description of the battery fault LED,
see Table 1-4. For information on removing and installing the BBU, see
"Removing and Installing a RAID Controller Module Backup Battery Unit"
on page 62.
NOTE: For virtual disks, the RAID controller firmware changes the data cache
setting based on the state of the battery. If the battery is missing or does not have
sufficient charge, the controller flushes the cache and sets the write cache
attribute to Write Through for all virtual disks. When the battery is replaced, Write
Back is reenabled.
The RAID controller module logs the age of the battery and issues a
replacement reminder message approximately six weeks before expiration.
After replacing the battery, you must use MD Storage Manager to reset the
battery age.
RAID Enclosure Thermal Shutdown
Enclosure management provides a feature that automatically shuts down the
enclosure when the temperature within the storage enclosure exceeds a safe
threshold. Thermal shutdown protects the data on the physical disks from
corruption in the event of cooling system failure. Because the battery backup
unit
protects against cache data loss for up to 72 hours,
all data in the cache is
saved. It is not necessary to shut down any expansion enclosures attached to
the storage enclosure.
Temperature threshold values are used to determine the temperature at
which shutdown occurs. These thresholds are default settings and cannot be
changed. If the temperature sensors on the backplane detect a temperature
exceeding the Nominal Failure Threshold, a critical event is set. If the
Maximum Failure Threshold is reached, shutdown of the enclosure power
supplies occurs within 3 minutes. A third threshold, the Shutdown Threshold,
shuts down the enclosure power supplies within 5 seconds after it is reached.
About Your System 23
Cache Functions and Features
Cache Mirroring
The cache mirroring function copies accepted host-write data from the
primary controller to the partner controller. This action ensures that hostwrite data is safely mirrored to the partner controller before successful
completion status is returned to the host. If a controller fails, the surviving
controller safely retains all mirrored data. Cache mirroring is enabled by
default.
Write-Back Cache
Write-back cache is a caching strategy whereby write operations result in a
completion signal being sent to the host operating system as soon as the
cache receives the data to be written. The target physical disk will receive the
data at a more appropriate time in order to increase controller performance.
In dual-active controller configurations with write-back caching enabled, the
write data is always copied to the cache of the second controller before
completion status is issued to the host initiator. Write Back is enabled by
default.
Write-Through Cache
Write-through cache is a caching strategy whereby data is written to the
physical disk before completion status is returned to the host operating
system. Write-through cache is considered more secure than write-back
cache, since a power failure is less likely to cause loss of data. The RAID
controller automatically switches to write-through if cache mirroring is
disabled or if the battery is missing or has a fault condition.
NOTE: Write cache settings are not user-configurable.
Power Supply and Cooling Fan Features
Your RAID enclosure supports two integrated, hot-pluggable power
supply/cooling fan modules. Both modules must be installed to ensure proper
cooling. Each module contains two separate cooling fans. The enclosure
requires at least three of the cooling fans to operate to avoid overheating.
24 About Your System
CAUTION: A power supply/cooling fan module can be removed from a powered-
on enclosure for a maximum period of no more than 5 minutes. Beyond that time,
the enclosure may automatically shut down to prevent damage to the enclosure
and/or enclosure components.
A power supply/cooling fan module can be replaced without powering down
the enclosure. For information on removing and replacing the modules, see
"Removing and Installing the Power Supply/Cooling Fan Module" on page 64.
Figure 1-7 shows the power supply/cooling fan module features and LED
indicators. Table 1-5 lists the LED indicator descriptions.
Figure 1-7. Power Supply and Cooling Fan Module LED Features and Indicators
14
2 3
6
1 DC power LED 2 Power supply/cooling fan
fault LED
4 cooling fans (2) 5 on/off switch 6 AC power connector
3AC power LED
About Your System 25
5
Table 1-5. Power Supply/Cooling Fan Module LED Indicators
Type Color Icon Function
DC power Green On: DC output voltages are within
specifications.
Off: No power or voltages not within
specifications.
Power
supply/cooling
fan fault
AC power Green On: AC input voltage is within specifications.
Amber On: DC output voltages are not within
specifications or one (or both) fans are in fault.
Off: No fault condition is present.
Off: No power or voltages not within
specifications.
26 About Your System
Using Your RAID Enclosure
This section covers the following information:
• Basic concepts of a RAID solution including physical disks, virtual disks,
and disk groups
• RAID levels supported by MD Storage Manager
• Hot spare operations and rebuilds
• Media errors and unreadable sectors
• RAID operations and features
• Advanced RAID features
• Hardware redundancy and failover including cabling
• Updating enclosure firmware
• Best practice recommendations
Physical Disks, Virtual Disks, and Disk Groups
Physical disks in your RAID array provide the physical storage capacity for
your data. Before you can begin writing data to the storage array, you must
configure the physical storage capacity into logical components, called disk
groups and virtual disks.
A disk group is a set of physical disks upon which multiple virtual disks are
created. The maximum number of physical disks supported in a disk group
is 30. You create disk groups from unconfigured capacity on your storage array.
A virtual disk is a partition in a disk group that is made up of contiguous data
segments of the physical disks in the disk group. A virtual disk consists of data
segments from all physical disks in the disk group. Virtual disks and disk
groups are set up according to how you plan to organize your data. For
example, you might have one virtual disk for inventory, a second virtual disk
for financial and tax information, and a third virtual disk for customer
information.
Using Your RAID Enclosure 27
All virtual disks in a disk group support the same RAID level. The RAID
enclosure supports up to 256 virtual disks (minimum size of 10 MB each) that
can be assigned to host servers. Each virtual disk is assigned a Logical Unit
Number (LUN) that is recognized by the host operating system.
Physical Disks
Only Dell-supported 3.0-Gbps SAS physical disks are supported in the storage
array. If the RAID controller module detects unsupported physical disks, it
marks the disk as unsupported and the physical disk becomes unavailable for
all operations.
NOTE: The MD3000i enclosure must contain at least two physical disks for proper
operation. This is necessary because the physical disks are used to store
configuration information.
Physical Disk States
The RAID controller module recognizes the physical disk states (mode and
status reported in MD Storage Manager) described in Table 2-1.
Table 2-1. RAID Controller Physical Disk States
Status Mode Description Physical Disk
Status LED
Indication
Optimal Unassigned The physical disk in the indicated
slot is unused and available to be
configured.
Optimal Assigned The physical disk in the indicated
slot is configured as part of a disk
group.
Optimal Hot Spare Standby The physical disk in the indicated
slot is configured as a hot spare.
Optimal Hot Spare In Use The physical disk in the indicated
slot is in use as a hot spare within
a disk group.
Steady Green
Steady Green
Steady Green
Steady Green
28 Using Your RAID Enclosure
Table 2-1. RAID Controller Physical Disk States (continued)
Status Mode Description Physical Disk
Status LED
Indication
Failed Assigned,
Unassigned, Hot
Spare In Use, or
Hot Spare Standby
Replaced Assigned The physical disk in the indicated
Pending
Failure
(none) (none) The indicated slot is empty, or the
Assigned,
Unassigned, Hot
Spare In Use, or
Hot Spare Standby
The physical disk in the indicated
slot has been failed because of an
unrecoverable error, an incorrect
drive type or drive size, or by its
operational state being set to
failed.
slot has been replaced and is ready
to be, or is actively being,
configured into a disk group.
A SMART error has been detected
on the physical disk in the
indicated slot.
array cannot detect the physical
disk.
Amber flashing
(125 ms)
Green flashing
(On 400 ms, Off
100 ms)
Flashing Green,
Amber, and off
Off
If a disk drive rebuild fails because of a source drive failure or because the
drive is too small, the user interface reports a failure of the physical disk even
though the LED state on the drive indicates the rebuild was aborted (green
for 3 seconds, amber for 3 seconds, then off for 3 seconds).
Self-Monitoring Analysis and Reporting Technology (SMART)
Self-Monitoring Analysis and Reporting Technology (SMART) monitors the
internal performance of all physical disk components to detect faults
indicating the potential for physical disk failure. SMART uses this
information to report whether failure is imminent so that a physical disk can
be replaced before failure occurs. The RAID controller monitors all attached
drives and notifies users when a predicted failure is reported by a physical
disk.
Using Your RAID Enclosure 29
Virtual Disks and Disk Groups
When configuring a storage array, you would normally proceed in this order:
• Organize the physical disks into disk groups.
• Create virtual disks within these disk groups.
• Determine which host servers you want to grant access to which virtual
disks, then create mappings to associate the virtual disks with the host
servers.
NOTE: Host server access must be created prior to mapping virtual disks to them.
Disk groups are always created in the unconfigured capacity of a storage array;
virtual disks are created within the free capacity of a disk group. Unconfigured
capacity is comprised of the available physical disk space that is not already
assigned in the storage array. Free capacity is the space in a disk group that has
not been assigned to a virtual disk.
Creating a Virtual Disk
To create a virtual disk, use one of the following methods:
• Create a new disk group from unconfigured capacity. You can define the
RAID level and capacity (the number of physical disks) for the disk group,
then define the parameters for the first virtual disk in the new disk group.
• Create a new virtual disk in the free capacity of an existing disk group. You
only need to specify the parameters for the new virtual disk.
Virtual Disk States
The RAID controller module recognizes the following virtual disk states.
Table 2-2. RAID Controller Virtual Disk States
State Description
Optimal The virtual disk contains physical disks that are all online.
Degraded The virtual disk with a redundant RAID level contains an inaccessible
physical disk. The system can still work properly, but performance may
be affected and additional disk failures may result in data loss.
Offline A virtual disk with one or more member disks in an inaccessible (failed,
missing, or offline) state. Data on the virtual disk is no longer
accessible.
30 Using Your RAID Enclosure
Loading...