Administrator Guide

Changing the virtual disk modification priority
You can specify the modification priority setting for a single virtual disk or multiple virtual disks on a storage array.
Guidelines to change the modification priority of a virtual disk:
• If more than one virtual disk is selected, the modification priority defaults to the lowest priority. The current priority is shown only if a
single virtual disk is selected.
• Changing the modification priority by using this option modifies the priority for the selected virtual disks.
To change the virtual disk modification priority:
1. In the AMW, select the Storage & Copy Services tab.
2. Select a virtual disk.
3. In the menu bar, select Storage > Virtual Disk > Change > Modification Priority.
The Change Modification Priority window is displayed.
4. Select one or more virtual disks. Move the Select modification priority slider bar to the desired priority.
NOTE: To select nonadjacent virtual disks, press <Ctrl> click and select the appropriate virtual disks. To select
adjacent virtual disks, press <Shift> click the appropriate virtual disks. To select all of the available virtual disks,
click Select All.
5. Click OK.
A message prompts you to confirm the change in the virtual disk modification priority.
6. Click Yes.
7. Click OK.
Changing virtual disk cache settings
You can specify the cache memory settings for a single virtual disk or for multiple virtual disks in a storage array.
Guidelines to change cache settings for a virtual disk:
• After opening the Change Cache Settings dialog, the system may display a window indicating that the RAID controller module has
temporarily suspended caching operations. This action may 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 your Technical
Support representative.
• If you select more than one virtual disk, the cache settings default to no settings selected. The current cache settings appear only if
you select a single virtual disk.
• If you change the cache settings by using this option, the priority of all the virtual disks that you selected is modified.
To change the virtual disk cache settings:
1. In the AMW, select the Storage & Copy Services tab and select a virtual disk.
2. In the menu bar, select Storage > Virtual Disk > Change > Cache Settings.
The Change Cache Settings window is displayed.
3. Select one or more virtual disks.
To select nonadjacent virtual disks, press <Ctrl> click. To select adjacent virtual disks, press <Shift> click. To select all the available
virtual disks, select Select All.
4. In the Cache Properties area, you can select:
• Enable read caching
• Enable write caching
○ Enable write caching without batteries — to permit write caching to continue even if the RAID controller module batteries
are discharged completely, not fully charged, or are not present.
○ Enable write caching with replication — to replicate cached data across two redundant RAID controller modules that have
the same cache size.
• Enable dynamic cache read prefetch
CAUTION:
Possible loss of data—Selecting the Enable write caching without batteries option lets write caching
continue even when the batteries are discharged completely or are not fully charged. Typically, write caching is
turned off temporarily by the RAID controller module until the batteries are charged. If you select this option and do
60 Disk groups, standard virtual disks, and thin virtual disks