AMCC 720-0138-00 manual Enabling and Disabling the Unit Write Cache

Setting Unit Policies

•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.

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.)

Write cache can be turned on or off for individual units in 3DMwithout changing the configuration or losing data from the drives.

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.

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