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Dell PowerVault MD3220i Owner's Manual - Page 43

Virtual Disk Operations, Virtual Disk Initialization, Background Initialization, Consistency Check

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The segment size or stripe element size specifies the size of data in a stripe written to a single disk. The storage array supports stripe element sizes of 8, 16, 32, 64, 128, 256, and 512 KB. The default stripe element size is 128 KB. Stripe width, or depth, refers to the number of disks involved in an array where striping is implemented. For example, a four-disk group with disk striping has a stripe width of four. NOTE: Although disk striping delivers excellent performance, striping alone does not provide data redundancy. Virtual Disk Operations Virtual Disk Initialization Every virtual disk must be initialized. Initialization can be done in the foreground or the background. A maximum of four virtual disks can be initialized concurrently on each RAID controller module. Background Initialization The storage array executes a background initialization when the virtual disk is created to establish parity, while allowing full host server access to the virtual disks. Background initialization does not run on RAID 0 virtual disks. The background initialization rate is controlled by MDSM. To change the rate of background initialization, you must stop any existing background initialization. The rate change is implemented when the background initialization restarts automatically. Foreground Initialization The storage array supports foreground initialization for virtual disks. All access to the virtual disk is blocked during foreground initialization. During foreground initialization, zeros (0x00) are written to every sector of the virtual disk. The virtual disk is available after foreground initialization is completed. Consistency Check A consistency check verifies the correctness of data in a redundant array (RAID levels 1, 5, 6, and 10). For example, in a system with parity, checking consistency involves computing the data on one physical disk and comparing the results to the contents of the parity physical disk. Planning: MD3200i Series Storage Array Terms and Concepts 43

Section	Page
Introduction	19
About This Document	19
Inside the box of the Dell PowerVault MD3200i Series Storage Array	19
Dell PowerVault MD3200i Series Storage Array	20
Dell PowerVault Modular Disk Storage Manager	20
Dell PowerVault Modular Disk Configuration Utility	20
Other Information You May Need	20
Planning: About Your Storage Array	23
Overview	23
Hardware Features	24
Front-Panel Features and Indicators	24
Back Panel Features and Indicators	27
Hard-Drive Indicator Patterns	28
Power Supply and Cooling Fan Features	29
Power Indicator Codes	30
Planning: RAID Controller Modules	31
RAID Controller Modules	31
RAID Controller Module Connectors and Features	32
RAID Controller Module-Additional Features	34
Battery Backup Unit	34
Storage Array Thermal Shutdown	34
System Password Reset	35
Cache Functions and Features	35
Cache Mirroring	35
Write-Back Cache	35
Write-Through Cache	36
Planning: MD3200i Series Storage Array Terms and Concepts	37
Physical Disks, Virtual Disks, and Disk Groups	37
Physical Disks	37
Physical Disk States	38
Self-Monitoring Analysis and Reporting Technology	39
Virtual Disks and Disk Groups	39
Virtual Disk States	40
RAID Levels	40
RAID Level Usage	41
Segment Size	42
Virtual Disk Operations	43
Virtual Disk Initialization	43
Background Initialization	43
Foreground Initialization	43
Consistency Check	43
Media Verification	44
Cycle Time	44
Virtual Disk Operations Limit	44
Disk Group Operations	45
RAID Level Migration	45
Segment Size Migration	45
Virtual Disk Capacity Expansion	46
Disk Group Expansion	46
Disk Group Defragmentation	46
Disk Group Operations Limit	46
RAID Background Operations Priority	47
Virtual Disk Migration and Disk Roaming	48
Disk Migration	48
Disk Roaming	50
Advanced Features	50
Host Server-to-Virtual Disk Mapping	50
Host Types	51
Snapshot Virtual Disks	51
Snapshot Repository Virtual Disk	52
Virtual Disk Copy	52
Virtual Disk Recovery	53
Using Snapshot and Disk Copy Together	53
Multi-Path Software	54
Preferred and Alternate Controllers and Paths	54
Virtual Disk Ownership	55
Load Balancing	55
Monitoring MD3200i Series System Performance	56
Configuration: Overview	59
User Interface	59
Enterprise Management Window	60
Array Management Window	61
Configuration: About Your Storage Array	63
Out-of-Band and In-Band Management	63
Storage Arrays	64
Adding Storage Arrays	64
Setting Up Your Storage Array	66
Locating Storage Arrays	67
Naming or Renaming Storage Arrays	68
Setting a Password	69
Viewing Storage Array Connections	70
Adding/Editing a Comment to an Existing Storage Array	71
Removing Storage Arrays	71
Enabling Premium Features	72
Failover Alert Display	72
Changing the Cache Settings on the Storage Array	72
Changing Expansion Enclosure ID Numbers	73
Changing the Enclosure Order in the Physical Pane	73
Configuring Alert Notifications	74
Configuring E-mail Alerts	74
Configuring SNMP Alerts	77
Battery Settings	78
Setting the Storage Array RAID Controller Module Clocks	79
Configuration: Using iSCSI	81
Changing the iSCSI Target Authentication	81
Entering Mutual Authentication Permissions	82
Creating CHAP Secrets	82
Initiator CHAP Secret	83
Target CHAP Secret	83
Valid Characters for CHAP Secrets	83
Changing the iSCSI Target Identification	84
Changing the iSCSI Target Discovery Settings	84
Configuring the iSCSI Host Ports	85
Advanced iSCSI Host Ports Settings	87
Viewing or Ending an iSCSI Session	88
Viewing iSCSI Statistics and Setting Baseline Statistics	89
Edit, Remove, or Rename Host Topology	90
Configuration: Event Monitor	91
Enabling or Disabling the Event Monitor	91
Windows	92
Linux	92
Configuration: About Your Host	93
Configuring Host Access	93
Using the Mappings Tab	94
Defining a Host	94
Removing Host Access	96
Managing Host Groups	96
Creating a Host Group	96
Moving a Host to a Different Host Group	97
Removing a Host Group	98
Host Topology	98
Starting or Stopping the Host Context Agent	99
I/O Data Path Protection	100
Managing Host Port Identifiers	101
Configuration: Disk Groups and Virtual Disks	103
Creating Disk Groups and Virtual Disks	103
Creating Disk Groups	104
Locating a Disk Group	106
Creating Virtual Disks	106
Changing the Virtual Disk Modification Priority	108
Changing the Virtual Disk Cache Settings	109
Changing the Segment Size of a Virtual Disk	111
Changing the I/O Type	112
Choosing an Appropriate Physical Disk Type	113
Physical Disk Security with Self Encrypting Disk	113
Creating a Security Key	116
Changing a Security Key	117
Saving a Security Key	119
Unlocking Secure Physical Disks	120
Erasing Secure Physical Disks	120
Configuring Hot Spare Physical Disks	121
Hot Spares and Rebuild	123
Global Hot Spares	123
Hot Spare Operation	123
Hot Spare Drive Protection	123
Enclosure Loss Protection	124
Host-to-Virtual Disk Mapping	126
Creating Host-to-Virtual Disk Mappings	126
Modifying and Removing Host-to-Virtual Disk Mapping	128
Changing Controller Ownership of the Virtual Disk	129
Removing Host-to-Virtual Disk Mapping	129
Changing the RAID Controller Module Ownership of a Disk Group	130
Changing the RAID Level of a Disk Group	131
Restricted Mappings	132
Changing the RAID Controller Module Ownership of a Virtual Disk or a Disk Group	133
Changing the RAID Level of a Disk Group	135
Storage Partitioning	136
Disk Group and Virtual Disk Expansion	137
Disk Group Expansion	137
Virtual Disk Expansion	138
Using Free Capacity	138
Using Unconfigured Capacity	138
Disk Group Migration	139
Export Disk Group	139
Exporting a Disk Group	139
Import Disk Group	140
Importing a Disk Group	140
Storage Array Media Scan	141
Changing Media Scan Settings	142
Suspending the Media Scan	143
Configuration: Premium Feature- Snapshot Virtual Disks	145
Creating a Snapshot Virtual Disk Using the Simple Path	146
About the Simple Path	146
Preparing Host Servers to Create the Snapshot Using the Simple Path	147
Creating a Snapshot Virtual Disk Using the Advanced Path	149
About the Advanced Path	149
Preparing Host Servers to Create the Snapshot Using the Advanced Path	151
Creating the Snapshot Using the Advanced Path	153
Specifying Snapshot Virtual Disk Names	154
Snapshot Repository Capacity	156
Re-creating Snapshot Virtual Disks	159
Disabling a Snapshot Virtual Disk	159
Preparing Host Servers to Re-create a Snapshot Virtual Disk	160
Re-creating a Snapshot Virtual Disk	161
Configuration: Premium Feature- Virtual Disk Copy	163
Creating a Virtual Disk Copy for an MSCS Shared Disk	164
Virtual Disk Read/Write Permissions	165
Virtual Disk Copy Restrictions	165
Creating a Virtual Disk Copy	166
Before you Begin	167
Virtual Disk Copy and Modification Operations	167
Create Copy Wizard	167
Failed Virtual Disk Copy	168
Preferred RAID Controller Module Ownership	168
Failed RAID Controller Module	168
Copy Manager	169
Copying the Virtual Disk	169
Storage Array Performance During Virtual Disk Copy	170
Setting Copy Priority	170
Stopping a Virtual Disk Copy	171
Recopying a Virtual Disk	172
Preparing Host Servers to Recopy a Virtual Disk	172
Recopying the Virtual Disk	173
Removing Copy Pairs	174
Configuration: Premium Feature- Upgrading to High-Performance- Tier	175
Configuration: Device Mapper Multipath for Linux	177
Overview	177
Using DM Multipathing Devices	178
Prerequisite Steps	178
Device Mapper Configuration Steps	179
Linux Host Server Reboot Best Practices	183
Important Information About Special Partitions	183
Limitations and Known Issues	184
Troubleshooting	185
Management: Firmware Downloads	187
Downloading RAID Controller and NVSRAM Packages	187
Downloading Both RAID Controller and NVSRAM Firmware	188
Downloading Only NVSRAM Firmware	190
Downloading Physical Disk Firmware	192
Downloading MD1200 Series Expansion Module EMM Firmware	194
Self-Monitoring Analysis and Reporting Technology (SMART)	196
Media Errors and Unreadable Sectors	196
Management: Installing Array Components	197
Recommended Tools	197
Front Bezel (Optional)	198
Removing the Front Bezel	198
Installing the Front Bezel	198
Hard Drives	199
Removing a Drive Blank	199
Installing a Drive Blank	200
Removing a Hard Drive	200
Installing a Hard Drive	202
Removing a Hard Drive From a Hard-Drive Carrier	202
Installing a Hard Drive Into a Drive Carrier	205
RAID Controller Module	205
Removing a RAID Controller Module Blank	205
Installing a RAID Controller Module Blank	206
Removing a RAID Controller Module	207
Installing a RAID Controller Module	208
Opening the RAID Controller Module	208
Closing the RAID Controller Module	209
RAID Controller Module Backup Battery Unit	210
Removing the RAID Controller Module Backup Battery Unit	210
Installing the RAID Controller Module Backup Battery Unit	211
Power Supply/Cooling Fan Module	211
Removing a Power Supply/Cooling Fan Module	211
Installing a Power Supply/Cooling Fan Module	214
Control Panel	215
Removing the Control Panel	215
Installing the Control Panel	216
Backplane	217
Removing the Backplane	217
Installing the Backplane	220
Management: Firmware Inventory	221
Viewing the Firmware Inventory	221
Management: System Interfaces	223
Microsoft Services	223
Virtual Disk Service	223
Volume Shadow-Copy Service	223
Troubleshooting: Your Storage Array Software	225
Start-Up Routine	225
Device Health Conditions	225
Storage Array Support Data	229
Automatically Collect the Support Bundle Data	229
Collecting the Physical Disk Data	230
Event Log	231
Recovery Guru	232
Storage Array Profile	232
Viewing the Logical Associations	234
Viewing the Physical Associations	234
Finding Nodes	235
Using Go To	236
Recovering From an Unresponsive Storage Array Condition	237
Locating a Physical Disk	240
Locating an Expansion Enclosure	241
Capturing the State Information	242
SMrepassist Utility	243
Unidentified Devices	244
Recovering From an Unidentified Storage Array	244
Starting or Restarting the Host Context Agent Software	246
Troubleshooting: Your Array	249
Safety First-For you and Your Array	249
Troubleshooting Storage Array Startup Failure	249
Troubleshooting Loss of Communication	249
Troubleshooting External Connections	249
Troubleshooting Power Supply/Cooling Fan Module	250
Troubleshooting Array Cooling Problems	251
Troubleshooting Expansion Enclosure Management Modules	251
Troubleshooting RAID Controller Modules	253
Troubleshooting Hard Drives	254
Troubleshooting Array and Expansion Enclosure Connections	255
Troubleshooting a Wet Storage Array	255
Troubleshooting a Damaged Array	256
Troubleshooting RAID Controller Modules	257
Conditions	257
Invalid Storage Array	257
ECC Errors	257
PCI Errors	258
Critical Conditions	258
Noncritical Conditions	258
Getting Help	259
Contacting Dell	259

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Planning: MD3200i Series Storage Array Terms and Concepts

The segment size or stripe element size specifies the size of data in a stripe

written to a single disk. The storage array supports stripe element sizes of 8,

16, 32, 64, 128, 256, and 512 KB. The default stripe element size is 128 KB.

Stripe width, or depth, refers to the number of disks involved in an array

where striping is implemented. For example, a four-disk group with disk

striping has a stripe width of four.

NOTE:

Although disk striping delivers excellent performance, striping alone does

not provide data redundancy.

Virtual Disk Operations

Virtual Disk Initialization

Every virtual disk must be initialized. Initialization can be done in the

foreground or the background. A maximum of four virtual disks can be

initialized concurrently on each RAID controller module.

Background Initialization

The storage array executes a background initialization when the virtual disk is

created to establish parity, while allowing full host server access to the virtual

disks. Background initialization does not run on RAID 0 virtual disks. The

background initialization rate is controlled by MDSM. To change the rate of

background initialization, you must stop any existing background

initialization. The rate change is implemented when the background

initialization restarts automatically.

Foreground Initialization

The storage array supports foreground initialization for virtual disks. All

access to the virtual disk is blocked during foreground initialization. During

foreground initialization, zeros (0x00) are written to every sector of the virtual

disk. The virtual disk is available after foreground initialization is completed.

Consistency Check

A consistency check verifies the correctness of data in a redundant array

(RAID levels 1, 5, 6, and 10). For example, in a system with parity, checking

consistency involves computing the data on one physical disk and comparing

the results to the contents of the parity physical disk.