Changing Virtual Disk Cache Settings

Use the Change Cache Settings option to specify the settings for a single , or for multiple virtual disks on a . Perform the following steps:

Important:

After opening the Change Cache Settings dialog, you might see an icon displayed next to the selected cache properties. This icon indicates that the has temporarily suspended caching operations. This might occur when a new battery is charging, when a RAID controller module has been removed, or if a mismatch in cache sizes has been detected by the RAID controller module. After the condition has cleared, the cache properties selected in the dialog become active. If the selected cache properties do not become active, contact Customer and Technical Support.
If more than one virtual disk is selected, the cache settings default to no settings selected. The current cache settings are only shown if a single virtual disk is selected.
Changing the cache settings using this option modifies the priority for all of the virtual disks you selected.

Select a virtual disk or virtual disks from the Logical View, and select Virtual Disk >> Change >> Cache Settings.

To enable , select the Enable read caching check box.

To enable , select the Enable write caching check box. The options in the following table become available:

Option

Result

Enable write caching with mirroring

Select this check box to mirror cached data across two redundant RAID controller modules that have the same cache size.

Enable write caching without batteries

Select this check box to allow write caching to continue even if the RAID controller module batteries are discharged completely, not fully charged, or are not present.

Caution: Risk of data loss -- Selecting the option allows write caching to continue even when the batteries are discharged completely or not fully charged. Normally, write caching is turned off temporarily by the RAID controller module until the batteries are charged. If you select this option without an uninterruptible power supply (UPS) for protection, or if you do not have RAID controller module batteries and you select Enable write caching without batteries option, you could lose data.

Caution: Possible loss of data -- When the Optional RAID controller module batteries parameter is enabled, select Enable write caching without batteries to prevent the risk of losing cached data if a RAID controller module fails or if a power failure occurs to the storage array. Select Write caching without batteries only if you have an UPS for backup power protection.

Note: Cache is automatically flushed after the Enable write caching check box is disabled.

To enable dynamic cache read , check the box next to Dynamic cache read prefetch.

The RAID controller module copies additional data blocks into the cache while it is reading and copying -requested data blocks from disk to cache.

Uncheck the box to disable dynamic cache read prefetch.

Click OK.

Click Yes.

Changing Virtual Disk Cache Settings

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