Dell PowerEdge RAID Controller 6E - Manual (Page 93)

Configuring and Managing RAID
93
Managing Preserved Cache
If a virtual disk becomes offline or is deleted because of missing physical
disks, the controller preserves the dirty cache from the virtual disk.
This preserved dirty cache, known as pinned cache, is preserved until you
import the virtual disk or discard the cache.
NOTE:
Certain operations, such as creating a new virtual disk, cannot be
performed if pinned cache exists. You have to enter the BIOS Configuration Utility to
resolve the situation before you boot to the operating system. Messages are
displayed notifying you that you must enter the BIOS Configuration Utility to discard
the pinned cache or import the virtual disks with the pinned cache.
CAUTION:
If there are any foreign configurations, it is strongly advised that you
import the foreign configuration before you discard the preserved cache.
Otherwise, you might lose data that belongs with the foreign configuration.
Perform the following steps to select whether to import the virtual disk or
discard the preserved cache.
1 On the VD Mgmt screen, click on a controller icon.
2 Press <F2> to display the menu of available actions.
3 Select Manage Preserved Cache.
A message displays advising you to import the foreign configuration before
you discard the preserved cache to avoid losing data belonging to the
foreign configuration. Confirm whether you want to continue.
The Manage Preserved Cache screen displays the affected virtual disks.
4 You can choose to discard the cache on the Manage Preserved Cache
screen. If you press Cancel, the process is cancelled and the Preserved
Cache Retained dialog box is displayed.
If you choose to discard the cache, you are prompted to confirm your
choice. If you choose to retain the cache, a message displays to notify you
that you cannot perform certain operations while the cache exists.
Click OK to continue.
Some operations, such as creating a new virtual disk, are not allowed if
preserved cache exists. A message warns you that you cannot perform the
operation while preserved cache exists. If you choose to clear a configuration,
and preserved cache exists, a message warns you that all data on all virtual
drives is lost and the preserved cache is discarded.
Dell_PERC6.2_UG.book Page 93 Wednesday, June 24, 2009 6:08 PM