Dell POWERVAULT MD3600I - Manual (Page 148)

An overall repository virtual disk that has this feature enabled returns read errors if the data is determined to be
inconsistent by the RAID controller module firmware. You can enable this option for overall repository virtual disks that
contain consistency information. RAID Level 1, RAID Level 5, and RAID Level 6 maintain redundancy information.
You can enable this option for overall repository virtual disks that contain consistency information. RAID Level 1, RAID
Level 5, and RAID Level 6 maintain redundancy information.
You can change the Pre-Read Consistency Check for an overall repository for the following storage objects:
• Snapshot group
• Snapshot virtual disk
• Consistency group member virtual disk
• Replicated Pair
The following guidelines apply:
• Changing the Pre-Read Consistency Check setting modifies the setting only for the overall repository that you
selected.
• The Pre-Read Consistency Check setting is applied to all individual repository virtual disks contained within the
overall repository.
• If an overall repository virtual disk that is configured with pre-read is migrated to a RAID level that does not
maintain consistency information, the metadata of the overall repository virtual disk continues to show that pre-
read is enabled. However, reads to that overall repository virtual disk ignores consistency pre-read. If the virtual
disk is subsequently migrated back to a RAID level that supports consistency, the option becomes available
again.
To create a consistency group snapshot virtual disk:
1. From the AMW, select the Storage & Copy Services tab.
2. Select Overall Repository → Change Pre-read Consistency Check.
3. Select Enable pre-read consistency check, and click OK.
NOTE: Enabling the option on overall repository virtual disks without consistency does not affect the virtual
disk. However, the attribute is retained for that overall repository virtual disk if it is ever changed to one with
consistency information.
4. Click Yes.
Increasing The Capacity Of An Overall Repository
An overall repository can contain multiple repository virtual disks. You can use the Increase Capacity option to increase
the storage capacity of an existing overall repository for the following storage objects:
• Snapshot group
• Snapshot virtual disk
• Consistency group member virtual disk
• Consistency group member snapshot virtual disk
• Replicated pair
Use this option when you receive a warning that the overall repository is in danger of becoming full. You can increase
the repository capacity by performing one of these tasks:
• Adding one or more existing repository virtual disks.
• Creating a new repository virtual disk using free capacity that is available on a disk group or disk pool.
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