Dell OpenManage Server Administrator Version 7.3 Software Support

Server Administrator Storage Management

Notes, Cautions, and Warnings

NOTE: A NOTE indicates important information that helps you make better use of your computer.

CAUTION: A CAUTION indicates either potential damage to hardware or loss of data and tells you how to avoid the problem.

WARNING: A WARNING indicates a potential for property damage, personal injury, or death.

Trademarks used in this text: PowerConnect Inc.

Intel is a registered trademark and Microsoft

Pentium

™

OpenManage

Windows

Xeon

Windows Server

™

Dell

, the Dell logo,

™

EqualLogic

Core

and

AMD Opteron

Dell Boomi

™

Compellent

Celeron

are registered trademarks of Intel Corporation in the U.S. and other countries.

™

AMD Phenom

MS-DOS

™

Windows Vista

Dell Precision

™

KACE

FlexAddress

AMD Sempron

and

, and

™

Active Directory trademarks of Microsoft Corporation in the United States and/or other countries. registered trademarks of Red Hat, Inc. in the United States and/or other countries. trademark of Novell Inc. in the United States and other countries. affiliates. United States and/or other countries.

Citrix

Xen

XenServer

and

XenMotion

VMware

are either registered trademarks or trademarks of Citrix Systems, Inc. in the

Virtual SMP

trademarks of VMware, Inc. in the United States or other countries.

Oracle

vMotion

IBM

is a registered trademark of Oracle Corporation and/or its

vCenter

is a registered trademark of International Business Machines

Corporation.

2013 - 05

Rev. A00

™

OptiPlex

™

Force10

™

are trademarks of Advanced Micro Devices, Inc.

Red Hat Enterprise Linux

is a registered trademark and

Novell

and

vSphere

™

Latitude

PowerEdge

™

Vostro

and

are either trademarks or registered

™

PowerVault

™

are trademarks of Dell

and

Enterprise Linux

SUSE

are registered trademarks or

™

AMD

are

is a

Contents

1 Overview.....................................................................................................................................15

What Is New In This Release?................................................................................................................................15

Before Installing Storage Management................................................................................................................. 15

Version Requirements For Controller Firmware And Drivers...........................................................................15

Supported Controllers...................................................................................................................................... 16

Supported Enclosures......................................................................................................................................16

Support For Disk And Volume Management....................................................................................................17

2 Getting Started...........................................................................................................................19

Launching Storage Management........................................................................................................................... 19

On Systems Running Microsoft Windows........................................................................................................19

On A System Running Linux And Any Remote System.....................................................................................19

User Privileges........................................................................................................................................................20

Using The Graphical User Interface....................................................................................................................... 20

Storage Object................................................................................................................................................. 20

Health............................................................................................................................................................... 20

Information/Configuration................................................................................................................................ 20

Using The Storage Management Command-Line Interface...................................................................................20

Displaying The Online Help.....................................................................................................................................20

Common Storage Tasks..........................................................................................................................................21

3 Understanding RAID Concepts............................................................................................... 23

What Is RAID?.........................................................................................................................................................23

Hardware And Software RAID......................................................................................................................... 23

RAID Concepts................................................................................................................................................. 23

RAID Levels...................................................................................................................................................... 24

Organizing Data Storage For Availability And Performance.................................................................................. 24

Choosing RAID Levels And Concatenation.............................................................................................................25

Concatenation.................................................................................................................................................. 25

RAID Level 0 (Striping)......................................................................................................................................26

RAID Level 1 (Mirroring)...................................................................................................................................27

RAID Level 5 (Striping With Distributed Parity)................................................................................................27

RAID Level 6 (Striping With Additional Distributed Parity)...............................................................................28

RAID Level 50 (Striping Over RAID 5 Sets)....................................................................................................... 29

RAID Level 60 (Striping Over RAID 6 Sets)....................................................................................................... 30

RAID Level 10 (Striped-Mirrors)....................................................................................................................... 31

RAID Level 1-Concatenated (Concatenated Mirror)........................................................................................32

Comparing RAID Level And Concatenation Performance......................................................................................33

No-RAID..................................................................................................................................................................34

4 Quick Access To Storage Status And Tasks........................................................................ 35

Storage Health........................................................................................................................................................35

Hot Spare Protection Policy................................................................................................................................... 35

Storage Component Severity..................................................................................................................................36

Storage Properties And Current Activity................................................................................................................ 36

Alerts Or Events...................................................................................................................................................... 37

Monitoring Disk Reliability On RAID Controllers.....................................................................................................37

Using Alarms To Detect Failures............................................................................................................................ 37

Using Enclosure Temperature Probes....................................................................................................................37

Rescanning To Update Storage Configuration Changes........................................................................................37

Time Delay In Displaying Configuration Changes...................................................................................................38

5 PCI Express Solid-State Device Support...............................................................................39

What Is PCIe-SSD?.................................................................................................................................................39

PCIe SSD Features..................................................................................................................................................39

PCIe SSD Sub-System Properties.......................................................................................................................... 39

PCIe Extender Cards...............................................................................................................................................40

Physical Device Properties.....................................................................................................................................40

Physical Device Tasks............................................................................................................................................42

Blinking And Unblinking A PCIe SSD............................................................................................................... 43

Enabling Full Initialization On A PCIe SSD........................................................................................................43

Preparing To Remove A PCIe SSD................................................................................................................... 44

Exporting The Log.............................................................................................................................................44

Adding PCIe SSDs To Fluid Cache Pool..................................................................................................................44

Removing PCIe SSDs From Fluid Cache Pool......................................................................................................... 45

PCIe SSD SubSystem Health.................................................................................................................................. 45

Backplanes.......................................................................................................................................................45

Backplane Firmware Version...........................................................................................................................45

6 Fluid Cache For DAS ................................................................................................................ 47

Fluid Cache Properties............................................................................................................................................47

Fluid Cache Disks....................................................................................................................................................48

Fluid Cache Disk Properties............................................................................................................................. 48

Fluid Cache Pool..................................................................................................................................................... 49

Fluid Cache Pool Properties.............................................................................................................................49

Physical Device Properties.............................................................................................................................. 49

Cache I/O Statistics................................................................................................................................................ 51

Cache Pool Usage............................................................................................................................................ 51

Viewing The Performance Of The Fluid Cache Disk........................................................................................ 51

License Settings..................................................................................................................................................... 51

7 Storage Information And Global Tasks..................................................................................53

Storage Properties..................................................................................................................................................53

Global Tasks............................................................................................................................................................53

Performing A Global Rescan............................................................................................................................ 53

Enabling Or Disabling A Smart Thermal Shutdown..........................................................................................54

Storage Controller Properties.................................................................................................................................54

Storage Components........................................................................................................................................56

8 Controllers.................................................................................................................................. 57

What Is A Controller?..............................................................................................................................................57

RAID Controller Technology: SCSI, SATA, ATA, And SAS..................................................................................... 57

SAS RAID Controllers.......................................................................................................................................57

RAID Controller Features........................................................................................................................................58

Controller — Supported RAID Levels.....................................................................................................................58

Controller — Supported Stripe Sizes..................................................................................................................... 58

RAID Controller Read, Write, Cache, And Disk Cache Policy.................................................................................59

Read Policy.......................................................................................................................................................59

Write Policy......................................................................................................................................................59

Cache Policy.....................................................................................................................................................60

Disk Cache Policy.............................................................................................................................................60

Background Initialization On PERC Controllers...................................................................................................... 60

Non-RAID Controller Description........................................................................................................................... 61

Non-RAID SCSI Controllers..............................................................................................................................61

Non-RAID SAS Controllers...............................................................................................................................61

Firmware Or Driver Versions.................................................................................................................................. 61

Firmware/Driver Properties..............................................................................................................................61

Controller Health.....................................................................................................................................................62

Controller Components.....................................................................................................................................62

Controllers Properties And Tasks...........................................................................................................................63

Controller Tasks......................................................................................................................................................66

Rescanning The Controller...............................................................................................................................67

Creating A Virtual Disk..................................................................................................................................... 67

Enabling The Controller Alarm......................................................................................................................... 67

Disabling The Controller Alarm........................................................................................................................ 68

Turning Off The Controller Alarm..................................................................................................................... 68

Testing The Controller Alarm........................................................................................................................... 68

Setting The Rebuild Rate..................................................................................................................................68

Resetting The Controller Configuration............................................................................................................69

Exporting The Controller Log File..................................................................................................................... 69

Foreign Configuration Operations.................................................................................................................... 70

Importing Foreign Configurations.....................................................................................................................72

Importing Or Recovering Foreign Configurations.............................................................................................73

Clearing Foreign Configuration........................................................................................................................ 73

Physical Disks In Foreign Virtual Disks............................................................................................................ 74

Setting Background Initialization Rate.............................................................................................................77

Setting The Check Consistency Rate............................................................................................................... 77

Setting The Reconstruct Rate.......................................................................................................................... 78

Setting The Redundant Path Configuration......................................................................................................79

Setting The Patrol Read Mode......................................................................................................................... 81

Starting And Stopping Patrol Read.................................................................................................................. 82

Changing The Controller Properties.................................................................................................................82

Managing The Physical Disk Power................................................................................................................ 83

Managing The Preserved Cache......................................................................................................................85

Encryption Key................................................................................................................................................. 86

Converting To Non-RAID Disks........................................................................................................................ 88

Converting To RAID Capable Disks.................................................................................................................. 88

Viewing Available Reports .....................................................................................................................................89

Available Reports............................................................................................................................................. 89

Viewing Patrol Read Report............................................................................................................................. 89

Viewing Check Consistency Report................................................................................................................. 89

Viewing Slot Occupancy Report...................................................................................................................... 90

Viewing Physical Disk Firmware Version Report.............................................................................................90

9 Enclosures And Backplanes................................................................................................... 93

Backplanes............................................................................................................................................................. 93

Enclosures.............................................................................................................................................................. 93

SMART Thermal Shutdown..............................................................................................................................94

Enclosure Physical Disks................................................................................................................................. 94

Enclosure Fans.................................................................................................................................................94

Enclosure Power Supplies............................................................................................................................... 95

Enclosure Temperature Probes....................................................................................................................... 96

Enclosure Management Modules (EMMs)...................................................................................................... 98

Enclosure And Backplane Health.................................................................................................................... 99

Enclosure And Backplane Properties And Tasks.......................................................................................... 100

Changing The Mode On 220S And 221S Enclosures.............................................................................................105

Enclosure Management........................................................................................................................................105

Identifying An Open Connector On The Enclosure...............................................................................................105

Enclosure Components.........................................................................................................................................106

10 Connectors............................................................................................................................. 107

Channel Redundancy And Thermal Shutdown.....................................................................................................107

Creating A Channel-Redundant Virtual Disk.........................................................................................................107

Creating A Physical Disk For Channel Redundant Virtual Disks On PERC Controllers.................................. 108

Connector Health..................................................................................................................................................108

Controller Information.................................................................................................................................... 108

Connector Components..................................................................................................................................108

Connector Properties And Tasks..........................................................................................................................108

Rescanning The Connector............................................................................................................................109

Rescanning A Controller Connector...............................................................................................................110

Logical Connector Properties And Tasks............................................................................................................. 110

Path Health.....................................................................................................................................................111

Clearing The Connectors Redundant Path View............................................................................................111

Connector Components..................................................................................................................................111

11 Tape Drive.............................................................................................................................. 113

Tape Drive Properties...........................................................................................................................................113

12 RAID Controller Batteries.................................................................................................... 115

Battery Properties And Tasks...............................................................................................................................115

Battery Properties.......................................................................................................................................... 115

Battery Tasks........................................................................................................................................................116

Battery — Available Tasks...................................................................................................................................116

Starting A Learn Cycle....................................................................................................................................116

Battery Transparent Learn Cycle................................................................................................................... 117

Initiating The Battery Delay Learn Cycle........................................................................................................117

To Locate Delay Learn Cycle In Storage Management........................................................................................117

13 Physical Disks Or Physical Devices...................................................................................119

Guidelines To Replace A Physical Disk Or Physical Device.................................................................................119

Adding A New Disk To The System...................................................................................................................... 119

For SCSI, SATA, And ATA Controllers............................................................................................................119

For SAS Controllers........................................................................................................................................120

Replacing A Physical Disk Receiving SMART Alerts........................................................................................... 120

Disk Is Part Of A Redundant Virtual Disk........................................................................................................120

Disk Is Not Part Of A Redundant Virtual Disk.................................................................................................120

Other Disk Procedures..........................................................................................................................................121

Physical Disk Or Physical Device Properties....................................................................................................... 121

Physical Disk Or Physical Device Tasks...............................................................................................................125

Physical Disk Tasks.............................................................................................................................................. 125

Blinking And Unblinking A Physical Disk ...................................................................................................... 126

Removing Dead Segments............................................................................................................................. 126

Preparing To Remove.....................................................................................................................................126

Rebuilding Data.............................................................................................................................................. 127

Canceling A Rebuild....................................................................................................................................... 127

Assigning And Unassigning Global Hot Spare............................................................................................... 127

Setting The Physical Disk Online Or Offline................................................................................................... 128

Performing A Clear Physical Disk And Cancel Clear..................................................................................... 128

Enabling Revertible Hot Spare....................................................................................................................... 129

Enabling Instant Encrypt Erase...................................................................................................................... 130

Convert To RAID Capable Disk.......................................................................................................................130

Convert To Non-RAID Disk.............................................................................................................................130

14 Virtual Disks........................................................................................................................... 131

Considerations Before Creating Virtual Disks...................................................................................................... 131

Virtual Disk Considerations For Controllers................................................................................................... 131

Virtual Disk Considerations For PERC S100, S110, And S300 Controllers.......................................................133

Virtual Disk Considerations On Systems Running Linux................................................................................ 133

Number Of Physical Disks Per Virtual Disk....................................................................................................133

Number Of Virtual Disks Per Controller..........................................................................................................134

Calculation For Maximum Virtual Disk Size....................................................................................................134

Channel-Redundant Virtual Disks.................................................................................................................. 134

Creating Virtual Disks........................................................................................................................................... 134

Reconfiguring Or Migrating Virtual Disks.............................................................................................................135

Starting And Target RAID Levels For Virtual Disk Reconfiguration And Capacity Expansion..............................135

Maintaining The Integrity Of Redundant Virtual Disks......................................................................................... 136

Rebuilding Redundant Information....................................................................................................................... 137

Managing Virtual Disk Bad Block Management.................................................................................................. 137

Recommendations For Clearing Bad Blocks........................................................................................................ 138

Virtual Disk Properties And Tasks........................................................................................................................ 139

Virtual Disk Properties....................................................................................................................................139

Virtual Disk Tasks...........................................................................................................................................141

Virtual Disk — Available Tasks............................................................................................................................ 141

Reconfiguring A Virtual Disk.......................................................................................................................... 142

Format, Initialize, Slow, And Fast Initialize.....................................................................................................142

Canceling Background Initialization.............................................................................................................. 142

Restoring Dead Segments..............................................................................................................................143

Deleting Data On the Virtual Disk...................................................................................................................143

Performing A Check Consistency...................................................................................................................143

Canceling A Check Consistency.................................................................................................................... 143

Pausing A Check Consistency........................................................................................................................143

Resuming A Check Consistency.....................................................................................................................143

Blinking And Unblinking A Virtual Disk...........................................................................................................143

Renaming A Virtual Disk.................................................................................................................................144

Canceling A Rebuild....................................................................................................................................... 144

Changing The Virtual Disk Policy................................................................................................................... 144

Replacing A Member Disk..............................................................................................................................144

Clearing Virtual Disk Bad Blocks....................................................................................................................144

Encrypting A Virtual Disk................................................................................................................................144

Create Virtual Disk Express Wizard......................................................................................................................145

Create Virtual Disk Express Wizard (Step 2).........................................................................................................146

Create Virtual Disk Advanced Wizard.................................................................................................................. 146

Create Virtual Disk Advanced Wizard (Step 2)..................................................................................................... 149

Create Virtual Disk Advanced Wizard (Step 3)..................................................................................................... 150

Span Edit...............................................................................................................................................................151

Virtual Disk Task: Reconfigure (Step 1 of 3)..........................................................................................................151

To Reconfigure A Virtual Disk: Step 1 of 3......................................................................................................152

Virtual Disk Task: Reconfigure (Step 2 of 3)..........................................................................................................153

To Reconfigure A Virtual Disk Expand Virtual Disk Capacity: Step 2 of 3...................................................... 154

Virtual Disk Task: Reconfigure (Step 3 of 3)..........................................................................................................154

Slow And Fast Initialize.........................................................................................................................................154

Considerations For Slow Initialize..................................................................................................................155

Formatting Or Initializing A Disk............................................................................................................................155

To Locate Virtual Disks Task In Storage Management..................................................................................155

Deleting A Virtual Disk..........................................................................................................................................155

To Delete A Virtual Disk................................................................................................................................. 156

To Locate Delete In Storage Management....................................................................................................156

Renaming A Virtual Disk....................................................................................................................................... 156

To Rename A Virtual Disk...............................................................................................................................156

To Locate Rename In Storage Management................................................................................................. 157

Changing The Policy Of A Virtual Disk..................................................................................................................157

Changing The Read, Write, Or Disk Cache Policy Of A Virtual Disk...............................................................157

To Locate Change Policy In Storage Management ...................................................................................... 157

Split Mirror............................................................................................................................................................157

Splitting A Mirror............................................................................................................................................157

To Locate Split Mirror In Storage Management ........................................................................................... 158

Unmirror................................................................................................................................................................158

To Unmirror.................................................................................................................................................... 158

To Locate Unmirror In Storage Management................................................................................................ 158

Assigning And Unassigning Dedicated Hot Spare............................................................................................... 158

Assigning A Dedicated Hot Spare..................................................................................................................159

Unassigning A Dedicated Hot Spare..............................................................................................................159

To Locate Assign Or Unassign Dedicated Hot Spare In Storage Management............................................ 159

Virtual Disk Task: Replace Member Disk (Step 1 of 2)..........................................................................................159

Replacing A Member Disk: (Step 1 of 2).........................................................................................................160

To Locate Replace Member Disk In Storage Management...........................................................................160

Virtual Disk Task: Replace Member Disk (Step 2 of 2)..........................................................................................160

Enabling Fluid Cache On Virtual Disks..................................................................................................................161

Disabling Fluid Cache On Virtual Disks.................................................................................................................161

Enabling Fluid Cache On Virtual Disk Partitions................................................................................................... 161

Disabling Fluid Cache On Virtual Disk Partitions.................................................................................................. 162

15 Moving Physical And Virtual Disks From One System To Another...............................163

Required Conditions..............................................................................................................................................163

SCSI And SAS Controllers..............................................................................................................................163

SAS Controller ...............................................................................................................................................163

Migrating SAS Virtual Disks To Another System..................................................................................................163

16 Protecting Your Virtual Disk With A Hot Spare................................................................ 165

Understanding Hot Spares................................................................................................................................... 165

Setting Hot Spare Protection Policy..................................................................................................................... 165

Dedicated Hot Spare Protection Policy......................................................................................................... 166

Global Hot Spare Protection Policy................................................................................................................166

Considerations For Hot Spare Protection Policy............................................................................................166

Considerations For Enclosure Affinity............................................................................................................167

Considerations For Hot Spares On PERC 5/E, PERC 5/i, PERC 6/E, PERC 6/I, And CERC 6/I Controllers...............167

Dedicated Hot Spare Considerations.............................................................................................................168

Considerations For Hot Spares On PERC S100 And PERC S300 Controllers.........................................................168

Size Requirements For Global Hot Spares On S100 And S300 Controllers.....................................................168

Global Hot Spare Considerations On A SAS 6/iR..................................................................................................168

17 CacheCade Using Solid-State Drives................................................................................ 171

Managing The CacheCade................................................................................................................................... 171

CacheCade Properties................................................................................................................................... 172

Creating A CacheCade................................................................................................................................... 172

Resizing The CacheCade................................................................................................................................173

Renaming The CacheCade.............................................................................................................................173

Blinking And Unblinking The CacheCade.......................................................................................................173

Deleting The CacheCade................................................................................................................................173

18 Troubleshooting.....................................................................................................................175

Common Troubleshooting Procedures.................................................................................................................175

Cables Attached Correctly............................................................................................................................. 175

System Requirements.................................................................................................................................... 175

Drivers And Firmware.................................................................................................................................... 176

Isolate Hardware Problems........................................................................................................................... 176

Rescan To Update Information On SCSI Controllers......................................................................................176

Replacing A Failed Disk..................................................................................................................................176

Using The Physical Disk Online Command On Select Controllers................................................................. 177

Recovering From Removing The Wrong Physical Disk..................................................................................178

Resolving Microsoft Windows Upgrade Problems........................................................................................ 178

Virtual Disk Troubleshooting.................................................................................................................................178

A Rebuild Does Not Work...............................................................................................................................178

A Rebuild Completes With Errors...................................................................................................................179

Cannot Create A Virtual Disk..........................................................................................................................179

A Virtual Disk Of Minimum Size Is Not Visible To Windows Disk Management............................................179

Virtual Disk Errors On Systems Running Linux...............................................................................................180

Problems Associated With Using The Same Physical Disks For Both Redundant And Non-Redundant

Virtual Disks....................................................................................................................................................180

Specific Problem Situations And Solutions..........................................................................................................180

Physical Disk Is Offline Or Displays An Error Status......................................................................................181

Receive A Bad Block Alert With Replacement, Sense, Or Medium Error..................................................... 181

Alerts 2146 Through 2150 Received During A Rebuild Or While A Virtual Disk Is Degraded.........................181

Alerts 2146 Through 2150 Received While Performing I/O, Consistency Check, Format, Or Other

Operation........................................................................................................................................................182

Read And Write Operations Experience Problems........................................................................................ 182

A Task Menu Option Is Not Displayed........................................................................................................... 182

A Corrupt Disk Or Drive Message Suggests Running Autocheck During A Reboot...................................... 182

Erroneous Status And Error Messages After A Windows Hibernation......................................................... 182

Storage Management May Delay Before Updating Temperature Probe Status...........................................182

Storage Management May Delay Displaying Storage Devices After Reboot............................................... 183

You Are Unable To Log Into A Remote System.............................................................................................. 183

Cannot Connect To Remote System Running Microsoft Windows Server 2003............................................183

Reconfiguring A Virtual Disk Displays Error In Mozilla Browser................................................................... 183

Physical Disks Are Displayed Under The Connector Object Instead Of The Enclosure Object.....................183

PCIe SSD Troubleshooting................................................................................................................................... 183

Peripheral Component Interconnect Express PCIe Solid-State Drive SSD Is Not Visible In The

Operating System...........................................................................................................................................184

PCIe SSD Is Not Visible In Disk Management In The Operating System.......................................................184

Fluid Cache For DAS............................................................................................................................................. 184

Fluid Cache tree is not seen in OMSS............................................................................................................184

Additional entries seen in the statistics chart................................................................................................184

Fluid Cache device is not seen in the operating system................................................................................ 184

On H310 I do not see any option for Fluid Cache............................................................................................184

Cannot add more than 64 VDs for caching.....................................................................................................184

Configured mode vs operational mode troubleshooting in cases of Pass Through and Write Through

operational mode........................................................................................................................................... 185

When the Fluid Cache node is selected, Fluid Cache details is not displayed.............................................. 185

Add PCIe SSD to Fluid Cache Pool fails......................................................................................................... 185

Blank graph or graph with minimal data is plotted........................................................................................ 185

19 Frequently Asked Questions................................................................................................187

Why Is A Rebuild Not Working?........................................................................................................................... 187

How To Avoid Removing The Wrong Disk............................................................................................................ 187

How Can I Safely Remove Or Replace A Physical Disk........................................................................................187

How Do I Recover From Removing The Wrong Physical Disk..............................................................................188

How Do I Identify The Firmware Version That Is Installed................................................................................... 188

Which Controllers Do I Have?...............................................................................................................................188

How Do I Turn Off An Alarm................................................................................................................................. 188

Which RAID Level Is Best For Me?.......................................................................................................................188

20 Supported Features.............................................................................................................. 189

Supported Features On The PERC 5/, PERC 6/, And CERC 6/I Controllers............................................................ 189

Controller Tasks Supported On The PERC 5/, PERC 6/, And CERC 6/I Controllers..........................................189

Battery Tasks Supported On The PERC 5/E, PERC 6/, And CERC 6/I Controllers............................................191

Connector Tasks Supported By The PERC 5/E, PERC 6/, And CERC 6/I Controllers.......................................192

Physical Disk Tasks Supported By The PERC 5/E, PERC 6/, And CERC 6/I Controllers.................................. 192

Virtual Disk Tasks Supported By The PERC 5/, PERC 6/, And CERC 6/I Controllers....................................... 193

Virtual Disk Specifications For The PERC 5/, PERC 6/, And CERC 6/I Controllers...........................................194

RAID Levels Supported By The PERC 5/E, PERC 6, And CERC 6/I Controllers................................................197

Read, Write, And Cache Policy Supported By The PERC 5/E, PERC 6, And CERC 6/I Controllers..................197

Enclosure Support On The PERC 5/, PERC 6/, And CERC 6/I Controllers........................................................198

Supported Features On The PERC Hardware Controllers.................................................................................... 198

Controller Tasks Supported On The PERC Hardware Controllers..................................................................199

Battery Tasks Supported On The PERC Hardware Controllers......................................................................201

Connector Tasks Supported By The PERC Hardware Controllers................................................................. 202

Physical Disk Tasks Supported By The PERC Hardware Controllers............................................................ 202

Virtual Disk Tasks Supported By The PERC Hardware Controllers................................................................203

Virtual Disk Specifications For The PERC Hardware Controllers...................................................................205

RAID Levels Supported By The PERC Hardware Controllers.........................................................................208

Read, Write, Cache And Disk Cache Policy Supported By The PERC Hardware Controllers........................208

Enclosure Support On PERC Hardware Controllers.......................................................................................209

Supported Features On The SAS 5iR, SAS 6iR, And PERC H200 Controllers........................................................209

Controller Tasks Supported On The SAS 5/iR, SAS 6/iR, And H200 Controllers.............................................210

Battery Tasks Supported On The SAS 5/iR, SAS 6/iR, And H200 Controllers.................................................211

Connector Tasks Supported On The SAS 5/iR, SAS 6/iR, And H200 Controllers............................................211

Physical Disk Tasks Supported On The SAS 5/iR, SAS 6/iR, And H200 Controllers....................................... 211

Virtual Disk Tasks Supported By The SAS 5/iR, SAS 6/iR, And H200 Controllers...........................................212

RAID Levels Supported By The SAS 5/iR, SAS 6/iR, And H200 Controllers....................................................213

Virtual Disk Specifications For The SAS 5/iR, SAS 6/iR, And PERC H200 Controllers....................................213

Read, Write, And Cache Policy Supported By The SAS 5/iR, SAS 6/iR, And H200 Controllers......................215

Enclosure Support On The SAS 5/iR, SAS 6/iR, And H200 Controllers...........................................................215

Supported Features On The PERC S100, PERC S110, And S300 Controllers.........................................................215

Controller Tasks Supported On The PERC S100, PERC S110, And S300 Controllers...................................... 216

Physical Disk Tasks Supported By The PERC S100, PERC S110, And S300 Controllers.................................216

Virtual Disk Tasks Supported By The PERC S100, PERC S110, And S300 Controllers.................................... 216

Virtual Disk Specifications For The PERC S100, PERC S110, And S300 Controllers....................................... 217

RAID Levels Supported By The PERC S100, PERC S110, And S300 Controllers............................................. 218

Read Write Cache And Disk Cache Policy Supported By The PERC S100, PERC S110, And S300

Controllers......................................................................................................................................................218

Enclosure Support On The PERC S100, PERC S110, And S300 Controllers.................................................... 219

Supported Features On The Non-RAID Controllers..............................................................................................219

Controller Tasks Supported On The Non-RAID Controllers........................................................................... 219

Battery Tasks Supported By Non-RAID Controllers...................................................................................... 220

Connector Tasks Supported On The Non-RAID Controllers.......................................................................... 220

Physical Disk Tasks Supported On The Non-RAID Controllers......................................................................220

Virtual Disk Tasks Supported By The Non-RAID Controllers.........................................................................221

Enclosure Support On The Non-RAID Controllers......................................................................................... 222

Enclosure And Backplane Features..................................................................................................................... 222

Enclosure And Backplane Tasks....................................................................................................................222

Maximum Supported Configuration For SAS Controllers..................................................................................... 223

21 Determining The Health Status For Storage Components............................................. 225

Health Status Rollup: Battery Is Charging Or Dead.............................................................................................. 225

Health Status Rollup: Physical Disks In A Virtual Disk Are Failed Or Removed................................................... 225

Health Status Rollup: Physical Disks In A Virtual Disk Are Unsupported, Partially, Or Permanently Degraded..226

Health Status Rollup: All Physical Disks In A Virtual Disk Are In Foreign State...................................................226

Health Status Rollup: Some Physical Disks In A Virtual Disk Are In Foreign State..............................................226

Health Status Rollup: Virtual Disk Is Degraded; Physical Disks Are Failed Or Rebuilding................................... 227

Health Status Rollup: Virtual Disk Is Failed...........................................................................................................227

Health Status Rollup: Unsupported Firmware Version......................................................................................... 227

Health Status Rollup: Enclosure Power Supply Failed Or Power Connection Removed......................................228

Health Status Rollup: One Enclosure Fan Is Failed...............................................................................................228

Health Status Rollup: One Enclosure EMM Is Failed............................................................................................228

Health Status Rollup: One Enclosure Temperature Probe Is Failed..................................................................... 229

Health Status Rollup: Lost Both Power Connections To The Enclosure...............................................................229

Health Status Rollup: One Or More Physical Disks Are Failed.............................................................................229

Health Status Rollup: Physical Disk Is Rebuilding................................................................................................ 230

Overview

Server Administrator Storage Management provides enhanced features for configuring the locally attached RAID and non-RAID disk storage on a system. Storage Management enables you to perform controller and enclosure functions for all supported RAID and non-RAID controllers and enclosures from a single graphical user interface (GUI) or commandline interface (CLI). The GUI is wizard-driven and includes features for novice and advanced users. The CLI is fully featured and scriptable. Using Storage Management, you can protect your data by configuring data-redundancy, assigning hot spares, or rebuilding failed physical disks. All users of Storage Management should be familiar with their storage environment and Storage Management.

Storage Management supports SCSI, SATA, ATA, and SAS but not Fibre Channel.

For information on Storage Management alerts, see the

What Is New In This Release?

This release of Storage Management provides the following new features:

• Added support for Fluid Cache for DAS for configuring and monitoring Fluid Cache using Peripheral Component Interconnect Express (PCIe) Solid-State Drives (SSDs).

• Added support for the following operating systems:

– Red Hat Enterprise Linux 5.9, 6.1, 6.2, and 6.4

– Novell SUSE Linux Enterprise Server 10 SP4 and 11 SP3

– VMware vSphere 5.0 U2, 5.1 U1, and 6.0

– Citrix XenServer 6.2

– Microsoft Windows Server 2012 Essentials

• Added support for configuring Fluid Cache using PCIe SSDs.

• Added support for Remaining Rated Write Endurance status for Statistical Analysis System (SAS) and Serial Advance Technology Attachment (SATA) SSD.

• Added support for web browsers:

Server Administrator Messages Reference Guide

– Google Chrome 21 and 22

– Safari 5.1.7 on Apple Mac OS X

• Added support for PERC controllers — Sets the PCIe link speed of the controller to PCIe Generation 2 or 3.

Before Installing Storage Management

The following sections describe considerations for installing Storage Management.

Version Requirements For Controller Firmware And Drivers

For Storage Management to function properly, the controllers must have the minimum required version of the firmware and drivers installed. The firmware and drivers listed in the supported version for these controllers. Later versions of the firmware and drivers are also supported. For the most recent driver and firmware requirements, contact your service provider.

Server Administrator Readme

refer to the minimum

NOTE: To download the latest storport driver, see the Microsoft Knowledge Base article KB943545 at support.microsoft.com.

If you install Storage Management without the minimum required firmware and drivers, Storage Management may not be able to display the controllers or perform other functions. Storage Management generates alerts 2131 and 2132 when it detects unsupported firmware or drivers on a controller.

For information on alert messages, see the

Server Administrator Messages Reference Guide

Supported Controllers

NOTE: The firmware and drivers listed in the for these controllers. Later versions of the firmware and drivers are also supported. For the most recent driver and firmware requirements, contact your service provider.

This release of Storage Management supports the following controllers.

Server Administrator Readme

refer to the minimum supported version

Supported RAID Controllers

Storage Management supports the following RAID controllers. For information on the technology used by the supported RAID controllers, see RAID Controller Technology: SCSI, SATA, ATA, and SAS.

• PERC 5/E

• PERC 5/i Integrated and PERC 5/i Adapter

• SAS 5/iR Integrated and SAS 5/iR Adapter

• PERC 6/E

• PERC 6/I Integrated and PERC 6/I Adapter

• PERC 6/I Modular

• SAS 6/iR controller

• PERC S100, PERC S110, and PERC S300

• PERC H200 Adapter, PERC H200 Integrated, and PERC H200 Modular

• PERC H800 Adapter, PERC H700 Adapter, PERC H700 Integrated, and PERC H700 Modular

• PERC H310 Adapter, PERC H310 Mini Monolithic, PERC H310 Mini Blades, PERC H710 Adapter, PERC H710 Monolithic, PERC H710 Mini Monolithic, PERC H710P Adapter, PERC H710P Monolithic, PERC H710P Mini Monolithic, and PERC H810 Adapter

NOTE: The PERC H200, PERC H7x0, and PERC H8x0 controllers support 3TB NL SAS hard drives, 3TB NL SATA hard drives, SATA SSDs, and SAS SSDs.

Supported Non-RAID Controllers

Storage Management supports the following non-RAID controllers:

• LSI PCI-e U320

• SAS 5/i Integrated

• SAS 5/E

• SAS 6 Gbps Adapter

Supported Enclosures

This release of Storage Management supports the following enclosures:

• 20xS and 21xS storage systems

• 220S and 221S storage systems

• MD1000 and MD1120 storage systems

• MD1200 and MD1220 storage systems

Support For Disk And Volume Management

Storage Management does not provide disk and volume management. To implement disk and volume management, you must use the native disk and volume management utilities provided by your operating system.

Getting Started

Server Administrator Storage Management is designed for system administrators who implement hardware RAID solutions and understand corporate and small business storage environments.

Storage Management enables you to configure the storage components attached to your system. These components include RAID and non-RAID controllers and the channels, ports, enclosures, and disks attached to them. Using Storage Management, you can configure and manage the controller functions without accessing the BIOS. These functions include configuring virtual disks and applying RAID levels and hot spares for data protection. You can initiate many other controller functions like rebuilds, troubleshooting, setting thresholds. Most functions can be configured and managed while the system remains online and continues to process requests.

Storage Management reports the status of storage components. When the status for a component changes, Storage Management updates the display for that component and sends an alert to the Alert Log.

In addition to status changes, Storage Management generates alerts for user actions such as creating or deleting a virtual disk and for many other events. Most alerts also generate SNMP traps.

Other than monitoring and reporting status, Storage Management does not automatically initiate actions independent of user input. (Automatic shutdown of enclosures that have exceeded a critical temperature is the only exception. For more information on automatic shutdown, see SMART Thermal Shutdown). Storage Management actions are user-initiated using wizards and drop-down menus. Storage Management does, however, report the actions taken by the controllers, which include generating alerts, initiating tasks, such as a rebuild, and making state changes.

NOTE: Storage Management reports the change in state of disks and other storage components as viewed by the controller.

Launching Storage Management

Storage Management is installed as a Server Administrator service. All Storage Management features are accessible by selecting the Storage object in the Server Administrator tree view. For more information on starting Server Administrator, see the

On Systems Running Microsoft Windows

To start a Server Administrator session on a local system running Microsoft Windows operating system, click the Server Administrator icon on your desktop and log in using an account with Administrator privileges.

NOTE: Administrative privileges are required for configuration purposes.

On A System Running Linux And Any Remote System

To start a Server Administrator session on a Linux or any remote system, click the Server Administrator icon on your desktop and log in using an account with Administrator privileges.

Or, open a web browser and type one of the following in the address field and press <Enter>:

https://<

localhost

where <

localhost

Server Administrator User’s Guide

>:1311

> is the assigned name for the managed system and 1311 is the default port.

https://<

IP address

where <

IP address

NOTE: Type https:// (not http://) in the address field to receive a valid response in your browser.

>:1311

> is the IP address for the managed system and 1311 is the default port.

User Privileges

Server Administrator provides security through the User, Power User, and Administrator user groups. Each user group is assigned a different level of access to the Server Administrator features.

The Administrator privileges are required to access all Storage Management features. Administrator privilege allows you to execute the drop-down menu tasks, launch wizards, and use the omconfig storage command-line interface commands. Without Administrator privileges, you cannot manage and configure the storage component.

User and Power User privileges allow you to view storage status, but not manage or configure storage. With User and Power User privileges, you can use the omreport storage command and not the omconfig storage command.

For more information on user groups and other Server Administrator security features, see the

User’s Guide

Server Administrator

Using The Graphical User Interface

The following sections describe how to access the Storage Management features using the Server Administrator graphical user interface (GUI).

Storage Object

The Server Administrator tree view displays a Storage object. The Storage Management features are accessible by selecting the Storage object or expanding the Storage object and selecting a lower-level object.

Related Links

Displaying The Online Help

Health

On the Properties page, click Health to view the status information for the storage components. Related Links

Storage Health

Information/Configuration

On the Properties page, click Information/Configuration to view the property information for a storage object. The Information/Configuration subtabs also have options for executing storage tasks or launching wizards.

Using The Storage Management Command-Line Interface

Storage Management has a fully featured command-line interface (CLI). For more information on CLI, see the

Administrator Command Line Interface User’s Guide

Server

Displaying The Online Help

Storage Management provides an extensive online Help. This Help is available from the Server Administrator graphical user interface when the Storage or lower-level tree view object is selected.

The online Help is available as:

• Context-sensitive Help — Each Storage Management page has a icon. Click this icon to display the context-sensitive online Help that describes the contents of the displayed page.

• Table of Contents — The table of contents is available in the page that displays the information when you access the context-sensitive Help.

Related Links

Storage Object

Common Storage Tasks

This section provides information on commonly performed storage tasks:

• Create and configure virtual disks (RAID configuration). For more information, see:

– Create Virtual Disk Express Wizard — This topic provides information on using the Express Wizard to

create a virtual disk. Using the Express Wizard is the quickest method for creating a virtual disk. The Express Wizard is appropriate for novice users.

– Create Virtual Disk Advanced Wizard — This topic provides information on using the Advanced Wizard

to create a virtual disk. The Advanced Wizard requires a good knowledge of RAID levels and hardware and is appropriate for advanced users.

– Virtual Disks — This topic provides detailed information regarding the virtual disk management. This

information includes controller-specific considerations that affect virtual disk creation and management.

• Assign a hot spare to the virtual disk — When a virtual disk uses a RAID level, you can assign a hot spare (backup physical disk) to rebuild data if a physical disk in the virtual disk fails.

– Protecting Your Virtual Disk With A Hot Spare — This topic provides information on hot spares and

controller-specific information.

• Perform a Check Consistency — The Maintaining The Integrity Of Redundant Virtual Disks task verifies the accuracy of the redundant data on a virtual disk.

• Reconfigure a Virtual Disk — To expand the capacity of a virtual disk you can add physical disks to the virtual disk. You can also change the RAID levels. For more information, see Virtual Disk Task: Reconfigure (Step 1 of 3).

Understanding RAID Concepts

Storage Management uses the Redundant Array of Independent Disks (RAID) technology to provide Storage Management capability. Understanding Storage Management requires an understanding of RAID concepts, as well as some familiarity with how the RAID controllers and operating system view disk space on your system.

Related Links

What Is RAID? Organizing Data Storage For Availability And Performance Choosing RAID Levels And Concatenation Comparing RAID Level And Concatenation Performance

What Is RAID?

RAID is a technology for managing the storage of data on the physical disks that reside or are attached to the system. A key aspect of RAID is the ability to span physical disks so that the combined storage capacity of multiple physical disks can be treated as a single, extended disk space. Another key aspect of RAID is the ability to maintain redundant data which can be used to restore data in the event of a disk failure. RAID uses different techniques, such as striping, mirroring, and parity, to store and reconstruct data. There are different RAID levels that use different methods for storing and reconstructing data. The RAID levels have different characteristics in terms of read/write performance, data protection, and storage capacity. Not all RAID levels maintain redundant data, which means for some RAID levels lost data cannot be restored. The RAID level you choose depends on whether your priority is performance, protection, or storage capacity.

NOTE: The RAID Advisory Board (RAB) defines the specifications used to implement RAID. Although RAB defines the RAID levels, commercial implementation of RAID levels by different vendors may vary from the actual RAID specifications. An implementation of a particular vendor may affect the read and write performance and the degree of data redundancy.

Hardware And Software RAID

RAID can be implemented with either hardware or software. A system using hardware RAID has a RAID controller that implements the RAID levels and processes data reads and writes to the physical disks. When using software RAID provided by the operating system, the operating system implements the RAID levels. For this reason, using software RAID by itself can slow the system performance. You can, however, use software RAID along with hardware RAID volumes to provide better performance and variety in the configuration of RAID volumes. For example, you can mirror a pair of hardware RAID 5 volumes across two RAID controllers to provide RAID controller redundancy.

RAID Concepts

RAID uses particular techniques for writing data to disks. These techniques enable RAID to provide data redundancy or better performance. These techniques include:

• Mirroring — Duplicating data from one physical disk to another physical disk. Mirroring provides data redundancy by maintaining two copies of the same data on different physical disks. If one of the disks in the mirror fails, the system can continue to operate using the unaffected disk. Both sides of the mirror contain the

same data always. Either side of the mirror can act as the operational side. A mirrored RAID disk group is comparable in performance to a RAID 5 disk group in read operations but faster in write operations.

• Striping — Disk striping writes data across all physical disks in a virtual disk. Each stripe consists of consecutive virtual disk data addresses that are mapped in fixed-size units to each physical disk in the virtual disk using a sequential pattern. For example, if the virtual disk includes five physical disks, the stripe writes data to physical disks one through five without repeating any of the physical disks. The amount of space consumed by a stripe is the same on each physical disk. The portion of a stripe that resides on a physical disk is a stripe element. Striping by itself does not provide data redundancy. Striping in combination with parity does provide data redundancy.

• Stripe size — The total disk space consumed by a stripe not including a parity disk. For example, consider a stripe that contains 64KB of disk space and has 16KB of data residing on each disk in the stripe. In this case, the stripe size is 64KB and the stripe element size is 16KB.

• Stripe element — A stripe element is the portion of a stripe that resides on a single physical disk.

• Stripe element size — The amount of disk space consumed by a stripe element. For example, consider a stripe that contains 64KB of disk space and has 16KB of data residing on each disk in the stripe. In this case, the stripe element size is 16KB and the stripe size is 64KB.

• Parity — Parity refers to redundant data that is maintained using an algorithm in combination with striping. When one of the striped disks fails, the data can be reconstructed from the parity information using the algorithm.

• Span — A span is a RAID technique used to combine storage space from groups of physical disks into a RAID 10, 50, or 60 virtual disk.

RAID Levels

Each RAID level uses some combination of mirroring, striping, and parity to provide data redundancy or improved read and write performance. For specific information on each RAID level, see Choosing RAID Levels And Concatenation.

Organizing Data Storage For Availability And Performance

RAID provides different methods or RAID levels for organizing the disk storage. Some RAID levels maintain redundant data so that you can restore data after a disk failure. Different RAID levels also entail an increase or decrease in the I/O (read and write) performance of a system.

Maintaining redundant data requires the use of additional physical disks. The possibility of a disk failure increases with an increase in the number of disks. Since the differences in I/O performance and redundancy, one RAID level may be more appropriate than another based on the applications in the operating environment and the nature of the data being stored.

When choosing concatenation or a RAID level, the following performance and cost considerations apply:

• Availability or fault-tolerance — Availability or fault-tolerance refers to the ability of a system to maintain operations and provide access to data even when one of its components has failed. In RAID volumes, availability or fault-tolerance is achieved by maintaining redundant data. Redundant data includes mirrors (duplicate data) and parity information (reconstructing data using an algorithm).

• Performance — Read and write performance can be increased or decreased depending on the RAID level you choose. Some RAID levels may be more appropriate for particular applications.

• Cost efficiency — Maintaining the redundant data or parity information associated with RAID volumes requires additional disk space. In situations where the data is temporary, easily reproduced, or non-essential, the increased cost of data redundancy may not be justified.

• Mean Time Between Failure (MTBF) — Using additional disks to maintain data redundancy also increases the chance of disk failure at any given moment. Although this option cannot be avoided in situations where redundant data is a requirement, it does have implications on the workload of the system support staff within your organization.

• Volume — Volume refers to a single disk non-RAID virtual disk. You can create volumes using external utilities like the O-ROM <Ctrl> <r>. Storage Management does not support the creation of volumes. However, you can

view volumes and use drives from these volumes for creation of new virtual disks or Online Capacity Expansion (OCE) of existing virtual disks, provided free space is available. Storage Management allows Rename and Delete operations on such volumes.

Choosing RAID Levels And Concatenation

You can use RAID or concatenation to control data storage on multiple disks. Each RAID level or concatenation has different performance and data protection characteristics.

The following topics provide specific information on how each RAID level or concatenation store data as well as their performance and protection characteristics:

• Concatenation

• RAID Level 0 (Striping)

• RAID Level 1 (Mirroring)

• RAID Level 5 (Striping With Distributed Parity)

• RAID Level 6 (Striping With Additional Distributed Parity)

• RAID Level 50 (Striping Over RAID 5 Sets)

• RAID Level 60 (Striping Over RAID 6 Sets)

• RAID Level 10 (Striping Over Mirror Sets)

• RAID Level 1-Concatenated (Concatenated Mirror)

• Comparing RAID Level And Concatenation Performance

• No-RAID

Related Links

Starting And Target RAID Levels For Virtual Disk Reconfiguration And Capacity Expansion

Concatenation

In Storage Management, concatenation refers to storing data on either one physical disk or on disk space that spans multiple physical disks. When spanning more than one disk, concatenation enables the operating system to view multiple physical disks as a single disk. Data stored on a single disk can be considered a simple volume. This disk could also be defined as a virtual disk that comprises only a single physical disk.

Data that spans more than one physical disk can be considered a spanned volume. Multiple concatenated disks can also be defined as a virtual disk that comprises more than one physical disk.

A dynamic volume that spans to separate areas of the same disk is also considered concatenated.

When a physical disk in a concatenated or spanned volume fails, the entire volume becomes unavailable. Because the data is not redundant, it cannot be restored by rebuilding from a mirrored disk or parity information. Restoring from a backup is the only option.

Because concatenated volumes do not use disk space to maintain redundant data, they are more cost-efficient than volumes that use mirrors or parity information. A concatenated volume may be a good choice for data that is temporary, easily reproduced, or that does not justify the cost of data redundancy. In addition, a concatenated volume can easily be expanded by adding an additional physical disk.

• Concatenates n disks as one large virtual disk with a capacity of n disks.

• Data fills up the first disk before it is written to the second disk.

• No redundant data is stored. When a disk fails, the large virtual disk fails.

• No performance gain.

• No redundancy.

RAID Level 0 (Striping)

RAID 0 uses data striping, which is writing data in equal-sized segments across the physical disks. RAID 0 does not provide data redundancy.

RAID 0 characteristics:

• Groups n disks as one large virtual disk with a capacity of (smallest disk size) *n disks.

• Data is stored to the disks alternately.

• No redundant data is stored. When a disk fails, the large virtual disk fails with no means of rebuilding the data.

• Better read and write performance.

RAID Level 1 (Mirroring)

RAID 1 is the simplest form of maintaining redundant data. In RAID 1, data is mirrored or duplicated on one or more physical disks. If a physical disk fails, data can be rebuilt using the data from the other side of the mirror.

RAID 1 characteristics:

• Groups n + n disks as one virtual disk with the capacity of Storage Management allow the selection of two disks when creating a RAID 1. Because these disks are mirrored, the total storage capacity is equal to one disk.

• Data is replicated on both the disks.

• When a disk fails, the virtual disk still works. The data is read from the mirror of the failed disk.

• Better read performance, but slightly slower write performance.

• Redundancy for protection of data.

• RAID 1 is more expensive in terms of disk space since twice the number of disks are used than required to store the data without redundancy.

disks. The controllers currently supported by

RAID Level 5 (Striping With Distributed Parity)

RAID 5 provides data redundancy by using data striping in combination with parity information. Rather than dedicating a physical disk to parity, the parity information is striped across all physical disks in the disk group.

RAID 5 characteristics:

• Groups n disks as one large virtual disk with a capacity of (n-1) disks.

• Redundant information (parity) is alternately stored on all disks.

• When a disk fails, the virtual disk still works, but it is operating in a degraded state. The data is reconstructed from the surviving disks.

• Better read performance, but slower write performance.

• Redundancy for protection of data.

RAID Level 6 (Striping With Additional Distributed Parity)

RAID 6 provides data redundancy by using data striping in combination with parity information. Similar to RAID 5, the parity is distributed within each stripe. RAID 6, however, uses an additional physical disk to maintain parity, such that each stripe in the disk group maintains two disk blocks with parity information. The additional parity provides data protection in the event of two disk failures. In the following image, the two sets of parity information are identified as P and Q.

RAID 6 characteristics:

• Groups n disks as one large virtual disk with a capacity of (n-2) disks.

• Redundant information (parity) is alternately stored on all disks.

• The virtual disk remains functional with up to two disk failures. The data is reconstructed from the surviving disks.

• Better read performance, but slower write performance.

• Increased redundancy for protection of data.

• Two disks per span are required for parity. RAID 6 is more expensive in terms of disk space.

RAID Level 50 (Striping Over RAID 5 Sets)

RAID 50 is striping over more than one span of physical disks. For example, a RAID 5 disk group that is implemented with three physical disks and then continues on with a disk group of three more physical disks would be a RAID 50.

It is possible to implement RAID 50 even when the hardware does not directly support it. In this case, you can implement more than one RAID 5 virtual disks and then convert the RAID 5 disks to dynamic disks. You can then create a dynamic volume that is spanned across all RAID 5 virtual disks.

RAID 50 characteristics:

• Groups n*s disks as one large virtual disk with a capacity of s*(n-1) disks, where s is the number of spans and is the number of disks within each span.

• Redundant information (parity) is alternately stored on all disks of each RAID 5 span.

• Better read performance, but slower write performance.

• Requires as much parity information as standard RAID 5.

• Data is striped across all spans. RAID 50 is more expensive in terms of disk space.

RAID Level 60 (Striping Over RAID 6 Sets)

RAID 60 is striping over more than one span of physical disks that are configured as a RAID 6. For example, a RAID 6 disk group that is implemented with four physical disks and then continues on with a disk group of four more physical disks would be a RAID 60.

+ 200 hidden pages