AMCC 3WARE 720-0138-00 - Manual (Page 55)

Setting Unit Policies
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Setting Continue on Source Error During Rebuild
The Continue on Source Error During Rebuild policy is available for units
which are redundant. (For units which are not redundant, this option is not
shown on the screen.) When this policy is set, ECC (Error Correcting Code)
errors are ignored when they are encountered during a rebuild. (ECC errors
are typically defects that have been detected in the drive since initialization.)
When this policy is not set, if a unit is rebuilding, the rebuild will abort when
it encounters an ECC error and the unit will be set back to Degraded.
Since enabling this policy could result in the loss of some source data in the
event of source errors, the default is to not enable this policy. Select this
option only if you want to ensure that a rebuild will complete successfully
without manual intervention. If the rebuild fails and
Continue on Source
Error During Rebuild is not selected, then you have the option to start
another rebuild manually. After completing a rebuild with this policy enabled,
it is recommended that you execute a file system check when the rebuild
completes. On Mac OS X, you can do this using the First Aid tab in the Disk
Utility—select the disk on the left and then click
Verify Disk . If verification
encounters problems, you can then use the Repair Disk option on the same
screen.
To set the Continue on Source Error During Rebuild policy in 3DM
1 Choose Management > Controller Settings from the menu bar in 3DM.
2 In the Unit Policies section of the Controller Settings page, check the
boxes to select the policies you want to be in effect for each unit
The page refreshes, and a message at the top confirms the change you
have made.
Enabling and Disabling Queuing for a Unit
Some drives support NCQ (Native Command Queuing), a feature that can
result in increased performance for applications that require a lot of random
access of data (usually server-type applications). This is accomplished by
causing command reordering to be done on the drive.
In order to make use of NCQ, the feature must be enabled at both the drive
and the controller.
You can see whether NCQ is supported and enabled for a particular drive in
the Drive Details window. For details, see “Drive Details window” on
page 92.