Server Administrator Storage Management 8.3 User’s Guide

Disk Cache Policy

Does my controller support this feature? See Supported Features.

NOTE: The Disk Cache Policy feature is not supported on solid-state disks (SSDs) and on SAS 12 Gbps Adapter.

The Disk Cache Policy feature is supported on Non-RAID SAS/SATA physical disks (HDDs) connected to PERC hardware controllers and on RAID SAS/SATA physical disks connected to Software RAID S130 controller. This feature is not dependent on the controller mode and can function as usual when the controller is running in RAID or HBA mode.

Set the physical disk caching policy of all members of a virtual disk by enabling the Disk Cache Policy. When this feature is enabled, the physical disk writes data to the physical disk cache before writing it to the physical disk. Because it is faster to write data to the cache than to a disk, enabling this feature improves system performance.

The following are the disk cache policy options for Non-RAID disks connected to a PERC hardware controller:

• Enabled — Disk Cache Policy is enabled.
• Disabled — Disk Cache Policy is disabled.
• Unchanged — The disk uses the default write cache mode.

  NOTE: The Unchanged option is applicable only for PERC 9 hardware controllers with the latest firmware version.

  NOTE: If you want to revert the Disk Cache Policy settings of the physical disks to the factory default settings, then you must restart the server.

NOTE: The default setting for Disk Cache Policy for virtual disks based on SATA drives is Enabled, and for virtual disks based on SAS drives is Disabled.

NOTE: For SAS 6i/R and PERC H200 family of controllers, the Disk Cache Policy setting is available only after creating the virtual disk.