3DM 2 Online Help

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 3DM and 3BM.

Unit Write Cache. Determines whether write cache is enabled for the unit. When the write cache is enabled, data is stored locally on the drive 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 drive 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.

Auto Verify. Determines whether Auto Verify is enabled for the unit (9000-series controllers only). When enabled, the Auto Verify policy causes a verify task to be performed automatically once every 24 hours. This feature is designed to make it easier to insure regular verification of units. If verify schedules have been enabled, then Auto Verify will run only in the scheduled verify time slots. When Auto Verify is disabled, you must manually specify when you want to verify a unit, even if you have set a verify schedule. For details, see Setting Auto Verify for a Unit.

Continue on Source Error During Rebuild. Determines whether ECC errors are ignored when they are encountered during a rebuild (9000-series controllers only). (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 Continue on Source Error During Rebuild.

| Queuing. Determines whether NCQ (Native 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.

Show Unit Policies on Controller Settings Page in 3DM

Related Topics
  Enabling and Disabling the Unit Write Cache
  Setting Auto Verify for a Unit
  Setting Continue on Source Error During Rebuild
  Enabling and Disabling Queuing for a Unit
  Setting the StorSave Profile for a Unit

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