Use the Change Cache Settings option to specify the settings for a single logical drive or for multiple logical drives on a storage subsystem.
Keep these guidelines in mind when you change cache settings for a logical drive:
After opening the Change Cache Settings dialog, you might see an icon shown next to the selected cache properties. This icon indicates that the controller has temporarily
suspended caching operations. This action might occur when a new battery is charging, when a controller has been removed,
or if a mismatch in cache sizes has been detected by the controller. After the condition has cleared, the cache properties
selected in the dialog become active. If the selected cache properties do not become active, contact your representative.
if you select more than one logical drive, the cache settings default to no settings selected. The current cache settings
are shown only if you select a single logical drive.
If you change the cache settings by using this option, the priority of all of the logical drives that you selected is modified.
In the Logical pane, select a logical drive, and select Logical Drive >>Change >> Cache Settings.
To modify multiple logical drives, select the logical drives in the Select logical drives area.To select nonadjacent logical
drives, press Ctrl+click. To select adjacent logical drives, press Shift+click. To select all of the available logical drives, click Select All.
To enable read caching, select the Enable read caching check box.
To set the cache read-ahead value, select or type a value in the Cache read-ahead multiplier spinner box.
To enable write caching, select the Enable write caching check box.
Select one of these options:
Enable write caching with mirroring – Select this check box to mirror cached data across two redundant controllers that have the same cache size.
Enable write caching without batteries – Select this check box to permit write caching to continue even if the controller batteries are discharged completely, not
fully charged, or are not present.
Attention:
Possible loss of data – Selecting the Enable write caching without batteries option lets write caching continue even when the batteries are discharged completely or not fully charged. Typically, write
caching is turned off temporarily by the controller until the batteries are charged. If you select this option and do not
have a universal power supply for protection, you could lose data. In addition, you could lose data if you do not have controller
batteries and you select the Enable write caching without batteries option.
Important:
When the Optional controller batteries option is enabled, the Enable write caching check box does not appear. The Enable write caching without batteries check box is still available, but it is not checked by default.
Note:
Cache is automatically flushed after the Enable write caching check box is disabled.
Click OK.
In the confirmation dialog, click Yes.
A progress dialog appears, which indicates the number of logical drives being changed. To stop any further logical drives
from being changed, click Cancel.