Dell PowerVault 745N - Manual (Page 47)

General Controller Commands
This section describes the general controller operations.
Rescan Controller
The Rescan Controller command can be used to check whether any new disks were attached after a configuration was set. To rescan the controller, perform
the following steps:
1. Right-click the controller you want to rescan.
2. Click Rescan Controller.
After the operation is finished, the console is refreshed and the newly attached disks (if there are any) will appear under the Array Disk Group object
and under the controller object.
Flush
The Flush command forces the PERC 4/DC and 4/SC controllers to write the contents of cache memory onto the virtual disks. You might want to use this option
if you find your application or disks in an unstable condition.
Enable Alarm
The Enable Alarm command enables the controller alarm setting. When enabled, the alarm sounds in the event of a device failure.
To enable the alarm sound, perform the following steps:
1. Right-click a controller.
2. Click Enable Alarm.
Disable Alarm
The Disable Alarm command disables the alarm. If disabled, the alarm does not sound in the event of a device failure.
To disable the alarm sound, perform the following steps:
1. Right-click a controller.
2. Click Disable Alarm.
Rebuild Rate
The Rebuild Rate command changes the rebuild rate settings. The rebuild rate is the fraction of the compute cycles dedicated to rebuilding failed drives. A
rebuild rate of 100 percent means the system is totally dedicated to rebuilding the failed drive.
During a rebuild, the complete contents of an array disk are reconstructed. A rebuild operation can occur during normal operation; however, it will degrade
performance. You can reduce the rebuild rate to maintain system performance during the rebuild operation; however, a reduced rebuild rate extends the
rebuild time.
NOTICE: The default rebuild rate is 30 percent. System performance might be degraded if you change the rebuild rate to a higher value than the
default.