Microsemi Adaptec ASR-8405E - Page 75

C.3.3.3 Preserving the Controller Cache
Note: This option is available in the uEFI interface only.
Follow the on-screen instructions to toggle the controller's cache preservation policy; clear the preserved
cache for one or more logical drives; and check the controller cache preservation state.
C.3.3.3.1 Enabling and Disabling Controller Cache Preservation
This option toggles the controller cache preservation state. With cache preservation enabled, the system
preserves the controller's DDR cache to prevent data loss in the event of (1) a power failure or unsafe
shutdown of external enclosures while the host system, with the controller, still has power; and (2)
connectivity problems with drives.
"Dirty pages" (data that have not been committed to disk) are restored to the cache when power is restored
and the logical drives on the controller are back online. Once the preserved cache is restored, the controller
ushes the data to disk using its normal scheduling mechanism.
Note: You cannot enable maxCache read and/or write caching on a controller with cache
preservation enabled. In addition, the following operations are not permitted on a
controller in the cache preserved state:
• Creating a logical drive
• Changing the Performance mode
• Running a consistency check
• Changing the RAID Level of a logical drive
• Forcing a logical drive online or ofine
• Changing the cache page size
To enable controller cache preservation:
1. Start the ARC utility in uEFI mode (see Ctrl-A or uEFI/HII? Unied Extensible Firmware Interface
(uEFI)Human Interaction Infrastructure Interface (HII)HII interfaceuEFI).
2. Scan for controllers, then select the controller you want.
3. Select Controller Settings.
4. Select Controller Conguration, then select Cache Preservation.
5. Select Enabled.
C.3.3.3.2 Clearing the Controller Cache
You can clear the preserved dirty cache (data not committed to disk) for a specic logical drive or for all
logical drives on the controller if you expect a failed enclosure or logical drive to remain ofine.
To clear the cache for all logical drives on the controller:
1. Start the ARC utility in uEFI mode (see Ctrl-A or uEFI/HII? Unied Extensible Firmware Interface
(uEFI)Human Interaction Infrastructure Interface (HII)HII interfaceuEFI).
2. Scan for controllers, then select the controller you want.
3. Select Controller Settings.
4. Select Clear Cache Preserved on Controller.
To clear the cache for a specic logical drive:
1. Start the ARC utility in uEFI mode (see Ctrl-A or uEFI/HII? Unied Extensible Firmware Interface
(uEFI)Human Interaction Infrastructure Interface (HII)HII interfaceuEFI).
2. Scan for controllers, then select the controller you want.
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Microsemi Proprietary and Condential. Installation and User's Guide Revision 5
Using the Microsemi Adaptec RAID Conguration Utility