Changing Logical Drive Cache Settings

Related Topics

Use this option to specify the cache memory settings for a single logical drive, or for multiple logical drives on a storage subsystem.

Procedure

1

Select a logical drive from the Logical View, then, select either the Logical Drive >> Change >> Cache Settings pull-down menu option, or Change >> Cache Settings from the right-mouse pop-up menu.

Result: The Cache Settings dialog is displayed with the current settings for the selected logical drive.

To modify multiple logical drives, select the logical drives in the Select logical drives area:

  • Press CTRL + click to select nonadjacent logical drives
  • Press Shift + click to select adjacent logical drives
  • Press Select All to choose all the available logical drives

Important:

  • If more than one logical drive is selected, the cache settings default to no settings selected. The current cache settings are ONLY shown if a single logical drive is selected.
  • Changing the cache settings using this option modifies the priority for ALL of the logical drives you selected.

2

To enable read caching, select the Enable read caching check box.

Result: Read operations from the host will be stored in controller cache memory.

3

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

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 allow write caching to continue even if the controller batteries are discharged completely, not full charged, or are not present.

Caution: Selecting the Cache Without Batteries 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 controller until the batteries are charged. If you select this option without a UPS for protection, you could lose data.

Note: Cache will automatically be flushed once the Enable write caching check box is disabled.

4

To set the cache read-ahead value, select or type a value in the Cache read-ahead multiplier spinner box.

Result: The controller will copy additional data blocks into the cache while it is reading and copying host-requested data blocks from disk to cache.

To disable cache read-ahead, select or type 0 in the Cache read-ahead multiplier spinner box.

5

Select OK.

Result: A confirmation dialog is displayed.

6

Select Yes.

Result: A progress dialog is displayed indicating the number of logical drives being changed. Select Cancel to stop any further logical drives from being changed.

7

Select OK to exit the dialog.

Related Topics

Learn About Cache Settings and Performance

Changing Storage Subsystem Cache Settings

Learn About Cache Memory Protection