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Dell PowerVault MD3600i Owner's Manual - Page 44

Consistency Check, Media Verification, Cycle Time, Foreground Initialization

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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. A consistency check is similar to a background initialization. The difference is that background initialization cannot be started or stopped manually, while consistency check can. NOTE: It is recommended that you run data consistency checks on a redundant array at least once a month. This allows detection and automatic replacement of unreadable sectors. Finding an unreadable sector during a rebuild of a failed physical disk is a serious problem, because the system does not have the redundancy to recover the data. Media Verification Another background task performed by the storage array is media verification of all configured physical disks in a disk group. The storage array uses the Read operation to perform verification on the space configured in virtual disks and the space reserved for the metadata. Cycle Time The media verification operation runs only on selected disk groups, independent of other disk groups. Cycle time is the time taken to complete verification of the metadata region of the disk group and all virtual disks in the disk group for which media verification is configured. The next cycle for a disk group starts automatically when the current cycle completes. You can set the cycle time for a media verification operation between 1 and 30 days. The storage controller throttles the media verification I/O accesses to disks based on the cycle time. 44 Planning: MD3600i Series Storage Array Terms and Concepts

Section	Page
Introduction	19
About This Document	19
Inside the Box of the Dell PowerVault MD3600i Series Storage Array	19
MD3600i Series Storage Array	20
Dell PowerVault Modular Disk Storage Manager	20
Dell PowerVault Modular Disk Configuration Utility	20
Other Information You May Need	21
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: MD3600i Series Storage Array Terms and Concepts	37
Physical Disks, Virtual Disks, and Disk Groups	37
Physical Disks	38
Physical Disk States	38
Self-Monitoring Analysis and Reporting Technology	39
Virtual Disks and Disk Groups	39
Virtual Disk States	40
RAID Levels	41
RAID Level Usage	41
Segment Size	43
Virtual Disk Operations	43
Virtual Disk Initialization	43
Consistency Check	44
Media Verification	44
Cycle Time	44
Virtual Disk Operations Limit	45
Disk Group Operations	45
RAID Level Migration	45
Segment Size Migration	46
Virtual Disk Capacity Expansion	46
Disk Group Expansion	46
Disk Group Defragmentation	47
Disk Group Operations Limit	47
RAID Background Operations Priority	47
Virtual Disk Migration and Disk Roaming	48
Disk Migration	48
Disk Roaming	50
Host Server-to-Virtual Disk Mapping	50
Host Types	51
Advanced Features	51
Snapshot Virtual Disks	52
Snapshot Repository Virtual Disk	52
Virtual Disk Copy	53
Virtual Disk Recovery	54
Using Snapshot and Disk Copy Together	54
Multi-Path Software	54
Preferred and Alternate Controllers and Paths	55
Virtual Disk Ownership	55
Load Balancing	56
Monitoring MD3600i Series System Performance	57
Configuration: Overview	61
User Interface	61
Enterprise Management Window	62
Array Management Window	63
Configuration: About Your Storage Array	65
Out-of-Band and In-Band Management	65
Storage Arrays	66
Adding Storage Arrays	66
Setting Up Your Storage Array	68
Locating Storage Arrays	70
Naming or Renaming Storage Arrays	70
Setting a Password	71
Viewing Storage Array Connections	73
Adding/Editing a Comment to an Existing Storage Array	73
Removing Storage Arrays	74
Enabling Premium Features	74
Displaying Failover Alert	75
Changing the Cache Settings on the Storage Array	75
Changing Expansion Enclosure ID Numbers	76
Changing the Enclosure Order in the Physical Pane	76
Configuring Alert Notifications	77
Configuring E-mail Alerts	77
Configuring SNMP Alerts	80
Battery Settings	81
Setting the Storage Array RAID Controller Module Clocks	82
Configuration: Using iSCSI	83
Changing the iSCSI Target Authentication	83
Entering Mutual Authentication Permissions	84
Creating CHAP Secrets	84
Initiator CHAP Secret	85
Target CHAP Secret	85
Valid Characters for CHAP Secrets	85
Changing the iSCSI Target Identification	86
Changing the iSCSI Target Discovery Settings	86
Configuring the iSCSI Host Ports	87
Advanced iSCSI Host Ports Settings	89
Viewing or Ending an iSCSI Session	90
Viewing iSCSI Statistics and Setting Baseline Statistics	91
Edit, Remove, or Rename Host Topology	92
Configuration: Event Monitor	93
Enabling or Disabling the Event Monitor	94
Windows	94
Linux	94
Configuration: About Your Host	95
Configuring Host Access	95
Using the Mappings Tab	96
Defining a Host	97
Removing Host Access	98
Managing Host Groups	99
Creating a Host Group	99
Moving a Host to a Different Host Group	100
Removing a Host Group	101
Host Topology	101
Starting or Stopping the Host Context Agent	102
I/O Data Path Protection	103
Managing Host Port Identifiers	104
Configuration: Disk Groups and Virtual Disks	107
Creating Disk Groups and Virtual Disks	107
Creating Disk Groups	108
Locating a Disk Group	110
Creating Virtual Disks	110
Changing the Virtual Disk Modification Priority	112
Changing the Virtual Disk Cache Settings	113
Changing the Segment Size of a Virtual Disk	115
Changing the I/O Type	116
Choosing an Appropriate Physical Disk Type	117
Physical Disk Security with Self Encrypting Disk	117
Creating a Security Key	120
Changing a Security Key	122
Saving a Security Key	124
Validate Security Key	125
Unlocking Secure Physical Disks	125
Erasing Secure Physical Disks	126
Configuring Hot Spare Physical Disks	126
Hot Spares and Rebuild	128
Global Hot Spares	128
Hot Spare Operation	129
Hot Spare Drive Protection	129
Enclosure Loss Protection	130
Host-to-Virtual Disk Mapping	131
Creating Host-to-Virtual Disk Mappings	132
Modifying and Removing Host-to-Virtual Disk Mapping	133
Changing Controller Ownership of the Virtual Disk	134
Removing Host-to-Virtual Disk Mapping	135
Changing the RAID Controller Module Ownership of a Disk Group	135
Changing the RAID Level of a Disk Group	137
Restricted Mappings	137
Changing the RAID Controller Module Ownership of a Virtual Disk or a Disk Group	139
Changing the RAID Level of a Disk Group	141
Storage Partitioning	141
Disk Group and Virtual Disk Expansion	143
Disk Group Expansion	143
Virtual Disk Expansion	144
Using Free Capacity	144
Using Unconfigured Capacity	144
Disk Group Migration	145
Export Disk Group	145
Exporting a Disk Group	145
Import Disk Group	146
Importing a Disk Group	146
Storage Array Media Scan	147
Changing Media Scan Settings	148
Suspending the Media Scan	149
Configuration: Premium Feature- Snapshot Virtual Disks	151
Creating a Snapshot Virtual Disk Using the Simple Path	153
About the Simple Path	153
Preparing Host Servers to Create the Snapshot Using the Simple Path	154
Creating a Snapshot Virtual Disk Using the Advanced Path	156
About the Advanced Path	156
Preparing Host Servers to Create the Snapshot Using the Advanced Path	157
Creating the Snapshot Using the Advanced Path	160
Specifying Snapshot Virtual Disk Names	161
Snapshot Repository Capacity	163
Re-Creating Snapshot Virtual Disks	166
Disabling a Snapshot Virtual Disk	166
Preparing Host Servers to Re-Create a Snapshot Virtual Disk	167
Re-Creating a Snapshot Virtual Disk	168
Configuration: Premium Feature- Virtual Disk Copy	169
Creating a Virtual Disk Copy for an MSCS Shared Disk	170
Virtual Disk Read/Write Permissions	171
Virtual Disk Copy Restrictions	172
Creating a Virtual Disk Copy	172
Before you Begin	173
Virtual Disk Copy and Modification Operations	173
Create Copy Wizard	174
Failed Virtual Disk Copy	174
Preferred RAID Controller Module Ownership	174
Failed RAID Controller Module	175
Copy Manager	175
Copying the Virtual Disk	175
Storage Array Performance During Virtual Disk Copy	177
Setting Copy Priority	177
Stopping a Virtual Disk Copy	178
Recopying a Virtual Disk	179
Preparing Host Servers to Recopy a Virtual Disk	179
Recopying the Virtual Disk	180
Removing Copy Pairs	181
Configuration: Premium Feature- Upgrading to High-Performance- Tier	183
Configuration: Device Mapper Multipath for Linux	185
Overview	185
Using DM Multipathing Devices	186
Prerequisites	186
Device Mapper Configuration Steps	187
Linux Host Server Reboot Best Practices	191
Important Information About Special Partitions	192
Limitations and Known Issues	193
Troubleshooting	194
Management: Firmware Downloads	197
Downloading RAID Controller and NVSRAM Packages	197
Downloading Both RAID Controller and NVSRAM Firmware	198
Downloading Only NVSRAM Firmware	201
Downloading Physical Disk Firmware	203
Downloading MD1200 Series Expansion Module EMM Firmware	205
Self-Monitoring Analysis and Reporting Technology (SMART)	206
Media Errors and Unreadable Sectors	207
Management: Installing Array Components	209
Recommended Tools	209
Front Bezel (Optional)	210
Removing the Front Bezel	210
Installing the Front Bezel	210
Hard Drives	211
Removing a Drive Blank	211
Installing a Drive Blank	212
Removing a Hard Drive	212
Installing a Hard Drive	214
Removing a Hard Drive From a Hard-Drive Carrier	215
Installing a Hard Drive Into a Drive Carrier	217
RAID Controller Module	217
Removing a RAID Controller Module Blank	217
Installing a RAID Controller Module Blank	218
Removing a RAID Controller Module	219
Installing a RAID Controller Module	220
Opening the RAID Controller Module	220
Closing the RAID Controller Module	221
RAID Controller Module Backup Battery Unit	222
Removing the RAID Controller Module Backup Battery Unit	222
Installing the RAID Controller Module Backup Battery Unit	223
Power Supply/Cooling Fan Module	224
Removing a Power Supply/Cooling Fan Module	224
Installing a Power Supply/Cooling Fan Module	226
Control Panel	227
Removing the Control Panel	227
Installing the Control Panel	228
Backplane	229
Removing the Backplane	229
Installing the Backplane	232
Management: Firmware Inventory	233
Viewing the Firmware Inventory	233
Management: System Interfaces	235
Microsoft Services	235
Virtual Disk Service	235
Volume Shadow-Copy Service	235
Troubleshooting: Your Storage Array Software	237
Start-Up Routine	237
Device Health Conditions	237
Storage Array Support Data	241
Automatically Collect the Support Bundle Data	241
Retrieving Trace Buffers	242
Collecting Physical Disk Data	244
Event Log	245
Recovery Guru	246
Storage Array Profile	246
Viewing the Logical Associations	248
Viewing the Physical Associations	248
Finding Nodes	249
Using Go To	250
Recovering From an Unresponsive Storage Array Condition	251
Locating a Physical Disk	254
Locating an Expansion Enclosure	255
Capturing the State Information	256
SMrepassist Utility	257
Unidentified Devices	258
Recovering From an Unidentified Storage Array	258
Starting or Restarting the Host Context Agent Software	261
Troubleshooting: Your Array	263
Safety First-For you and Your Array	263
Troubleshooting Storage Array Startup Failure	263
Troubleshooting Loss of Communication	263
Troubleshooting External Connections	263
Troubleshooting Power Supply/Cooling Fan Module	264
Troubleshooting Array Cooling Problems	265
Troubleshooting Expansion Enclosure Management Modules	265
Troubleshooting RAID Controller Modules	266
Troubleshooting Hard Drives	268
Troubleshooting Array and Expansion Enclosure Connections	269
Troubleshooting a Wet Storage Array	269
Troubleshooting a Damaged Array	270
Troubleshooting RAID Controller Modules	271
Conditions	271
Invalid Storage Array	271
ECC Errors	271
PCI Errors	272
Critical Conditions	272
Noncritical Conditions	272
Getting Help	273
Contacting Dell	273

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Planning: MD3600i Series Storage Array Terms and Concepts

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.

A consistency check is similar to a background initialization. The difference is

that background initialization cannot be started or stopped manually, while

consistency check can.

NOTE:

It is recommended that you run data consistency checks on a redundant

array at least once a month. This allows detection and automatic replacement of

unreadable sectors. Finding an unreadable sector during a rebuild of a failed

physical disk is a serious problem, because the system does not have the

redundancy to recover the data.

Media Verification

Another background task performed by the storage array is media verification

of all configured physical disks in a disk group. The storage array uses the

Read operation to perform verification on the space configured in virtual

disks and the space reserved for the metadata.

Cycle Time

The media verification operation runs only on selected disk groups,

independent of other disk groups. Cycle time is the time taken to complete

verification of the metadata region of the disk group and all virtual disks in

the disk group for which media verification is configured. The next cycle for a

disk group starts automatically when the current cycle completes. You can set

the cycle time for a media verification operation between 1 and 30 days. The

storage controller throttles the media verification I/O accesses to disks based

on the cycle time.