AMCC 720-0138-00 Manual Do Utilizador

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Setting Unit Policies
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47
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 
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.