Dell 34XX, 38XX, 32XX, 36XX Syntax Applicable To Only One Virtual Disk, SnapVirtualDisk command

preReadConsistencyCheck=(TRUE FALSE) readCacheEnabled=(TRUE FALSE) writeCacheEnabled=(TRUE FALSE) cacheReadPrefetch=(TRUE FALSE)

Syntax Applicable To Only One Virtual Disk

set (virtualDisk ["virtualDiskName"] virtualDisk <wwID>) addCapacity=virtualDiskCapacity [addPhysicalDisks=(enclosureID1,drawerID1,slotID1 ...

enclosureIDn,drawerIDn,slotIDn)]

consistencyCheckEnabled=(TRUE FALSE) segmentSize=segmentSizeValue userLabel=virtualDiskName

preReadConsistencyCheck=(TRUE FALSE)

preReadConsistencyCheck

The setting to turn on or turn off preread consistency checking. Turning on preread consistency checking verifies the consistency of RAID redundancy data for the stripes containing the read data. Preread consistency checking is performed on read operations only. To turn on preread consistency checking, set this parameter to TRUE. To turn off preread consistency checking, set this parameter to

FALSE.

NOTE: Do not use this parameter on non-redundant virtual disks, such as RAID 0 virtual disks.

Guidelines while using the Pre-Read Consistency Check option:

•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.

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.

Setting Snapshot Virtual Disk Repository Virtual Disk Capacity

To increase or decreases the capacity of a snapshot virtual disk repository virtual disk, use the set

snapVirtualDisk command.

A snapshot repository virtual disk is an expandable virtual disk that is structured as a concatenated collection of up to 16 standard virtual disk entities. Initially, an expandable repository virtual disk has only a single element. The capacity of the expandable repository virtual disk is exactly that of the single element. You can increase the capacity of an expandable repository virtual disk by attaching additional standard virtual disks to it. The composite expandable repository virtual disk capacity then becomes the sum of the capacities of all of the concatenated standard virtual disks.

A snapshot group repository virtual disk must satisfy a minimum capacity requirement that is the sum of the following:

•32 MB to support fixed overhead for the snapshot group and for copy-on-write processing.

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