HP Storage Essentials V5.1 User Guide First Edition (T4283-96026, August 2006)

Storage Essentials 5.1 User Guide 353
1. Click the button corresponding to the volume you want to modify.
2. Type the cache read ahead multiplier (0 to 65535 bytes) in the Cache read-ahead multiplier
field.
A cache read ahead multiplier copies additional data blocks into the cache while it is reading
and copying host-requested data blocks from disk to cache. To disable this option, type 0.
3. (Optional) Select Read Caching.
When this option is enabled, the host's operations are stored in controller cache memory.
4. (Optional) Select Write Caching.
When this option is selected, data is written to the cache memory of a controller
5. (Optional) Select Write Caching with Mirroring.
Use this option to preserve data if a controller or the cache fails. When this option is enabled,
the data is written to two redundant controllers of the same cache size. This configuration
provides redundancy in case a controller fails. One controller performs uncompleted write
operations when the other controller fails.
NOTE: See ”Changing the Owner of a Volume (Engenio, CLARiiON and Sun 6130)” on
page 353 for information about changing the owner assigned to the volume.
Changing the Owner of a Volume (Engenio, CLARiiON and Sun 6130)
When a volume is created, the management server automatically assigns a controller to be the
owner of the volume. You can change the owning controller if you want to use a different one for
LUN masking.
NOTE: If the owner becomes unreachable as a result of a network failure or the owner itself fails,
the other controller in the pair automatically becomes the owner of the volume.
To change the owner:
1. Click the button corresponding to the volume you want to modify.
2. Select the owner for the volume from the Current Owner drop-down menu.
3. Click OK.
Managing Storage Pools
This section describes the following:
• ”Creating a Storage Pool (Engenio, CLARiiON, Sun 6130 and Sun 35xx)” on page 354
• ”Accessing Information About Storage Pools” on page 354
• ”Deleting a Storage Pool (Engenio and CLARiiON Only)” on page 355