AMCC 3WARE 720-0138-00 - Manual (Page 53)

Setting Unit Policies
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• StorSave Profile. Determines what StorSave profile is used for the unit.
Three profiles are available: Protection, Balanced, and Performance. For
details, see “Setting the StorSave Profile for a Unit” on page 48.
Figure 21. Unit Policies on Controller Settings Page in 3DM
Enabling and Disabling the Unit Write Cache
Write cache is used to store data locally in memory on the drive before it is
written to the disk drive media, allowing the computer to continue with its
next task. This improves performance. However, there may be instances when
you want the computer to wait for the drive to write all the data to disk before
going on to its next task. In this case, you must disable the write cache.
Write cache can be turned on or off for individual units in 3DMwithout
changing the configuration or losing data from the drives.
Note: If write cache is enabled, in the event of a power failure, the data in the write
cache will be lost.To avoid a sudden power failure, it is advisable to have an
Uninterruptable Power Supply (UPS). (BBU is not supported on the 9590SE-4ME.)
Note: If the Write Cache checkbox is disabled (not selectable), check to see if the
unit has degraded. If a unit has a StorSave policy of “Protect” and the unit degrades,
the policy prevents write cache from being re-enabled until the unit has been rebuilt.