Setting Unit Policies

The following polices are set when you create a unit, and can be adjusted later through settings on the Management >> Controller Settings pages of 3DM2 and the Policy Control screen in 3BM.

Write Cache. Determines whether write cache is enabled for the unit. When the write cache is enabled, data is stored locally on the controller before it is written to disk, allowing the computer to continue with its next task. This provides the most efficient access times for your computer system. When disabled, the computer will wait for the controller to write all the data to disk before going on to its next task. For details, see Enabling and Disabling the Unit Write Cache.

This feature interacts with functionality of the BBU, if you have one, and with the unit’s StorSave profile. For details, see Enabling and Disabling the Unit Write Cache.

Read Cache. Determines whether Intelligent or Basic Read Cache is enabled, or whether Read Cache is disabled. Setting the appropriate type of Read Cache can improve performance for different types of applications. For details, see Working with Read Cache Settings.

Auto-Verify. Determines whether the unit will be automatically verified at a time determined by the Verify Schedule. Enabling this feature helps insure that the unit is verified on a regular basis. For details, see Enabling or Disabling Auto-Verify for a Unit.

Override ECC (Continue on Source Error When Rebuilding). Determines whether ECC errors are ignored when they are encountered during a rebuild. (ECC errors are an indication of errors that have occurred on a particular drive since it was last read.) When not enabled, a rebuild will abort upon encountering an ECC error and the unit will be set to Degraded. For details, see Setting Overwrite ECC (Continue on Source Error When Rebuilding).

Queuing. Determines whether command queuing is enabled for the unit. When enabled for drives that support it, this policy can improve performance. For details, see Enabling and Disabling Queuing for a Unit.

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.

Rapid RAID Recovery. Determines which Rapid RAID Recovery option to use, All, Rebuild or Disable. All will apply the policy to both rebuilds and unclean shutdowns. Rebuild will apply only to rebuilds. You can switch between All and Rebuild settings, but, once Rapid RAID Recovery is disabled for the unit, it cannot be re-enabled. For details, see Rapid RAID Recovery.

Show Unit Policies on Controller Settings Page in 3DM2

Related Topics: Enabling and Disabling the Unit Write Cache; Working with Read Cache Settings; Enabling or Disabling Auto-Verify for a Unit; Setting Overwrite ECC (Continue on Source Error When Rebuilding); Enabling and Disabling Queuing for a Unit; Setting the StorSave Profile for a Unit; Rapid RAID Recovery