Dell MD3620F Computer Hardware User Manual


 
106 Configuration: Disk Groups and Virtual Disks
To change the virtual disk cache settings:
1
In the AMW, select the
Logical
tab and select a virtual disk
2
In the toolbar, select
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 of the available virtual disks,
click
Select All
.
4
In the
Select cache properties
area, you can select:
Enable read caching
—to enable read caching.
Enable dynamic cache read prefetch
—to enable dynamic cache
read prefetch.
Enable write caching
—to enable write caching.
Enable write caching with mirroring
—to mirror cached data
across two redundant RAID controller modules that have the
same cache size.
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.
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 not have a universal power supply for protection, you could lose data.
In addition, you could lose data if you do not have RAID controller module batteries
and you select the Enable write caching without batteries option.
NOTE: When the Optional RAID controller module batteries option is enabled,
the Enable write caching does not appear. The Enable write caching without
batteries is still available, but it is not checked by default.
NOTE: Cache is automatically flushed after the Enable write caching check
box is disabled.
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