Users Guide

the reconstruct task. At 0%, the reconstruct has the lowest priority for the controller, takes maximum time to complete, and
has least impact to system performance. A reconstruct rate of 0% does not mean that the reconstruct is stopped or paused.
At 100%, the reconstruct is the highest priority for the controller, the reconstruct time is minimized, and has most impact to
system performance.
To Change The Reconstruct Rate For A Controller
1. Type a numerical value in the Set New Reconstruct Rate (0-100) field. The value must be within the 0–100 range.
2. Click Apply Changes. To exit and cancel your changes, click Return to Previous Page.
To Locate Set Reconstruct Rate In Storage Management
1. In the Server Administrator window, under the system tree, expand Storage to display the controller objects.
2. Select a controller object.
3. Click Information/Configuration on the controller Properties page.
4. Select Set Reconstruct Rate from the Available Tasks drop-down menu.
5. Select Execute.
You can also locate this task from the Change Controller Properties drop-down menu.
Setting The Patrol Read Mode
NOTE: This task is not supported on PERC hardware controllers running in HBA mode.
Does my controller support this feature? See Supported Features.
Patrol read identifies disk errors in order to avoid disk failures and data loss or corruption. The Set Patrol Read task is
applicable only for disks used as virtual disks or hot spares.
The Set Patrol Read task runs in the background and corrects, when possible. When the Set Patrol Read mode is set to
Auto, patrol read is initiated when the controller is idle for a period of time and when no other background tasks are active. In
this scenario, the patrol read enhances the system performance as disk errors can be identified and corrected when there is not
input/output activity on the disk.
The controller adjusts the amount of system resources dedicated for patrol read based on the amount of controller activity that
is competing with the Patrol Read task. When the controller activity is high, fewer system resources are dedicated to the patrol
read task.
Patrol Read does not run on a physical disk in the following circumstances:
● The physical disk is not included in a virtual disk or is assigned as a hot spare.
● The physical disk is included in a virtual disk that is currently undergoing one of the following:
○ Rebuild
○ Reconfiguration or reconstruction
○
Background initialization
○ Check consistency
In addition, the Patrol Read suspends during heavy I/O activity and resumes when the I/O is finished.
To Set The Patrol Read Mode
Select the desired Patrol Read Mode option. The options available are:
● Auto — Initiates the Patrol Read task. After the task is complete, it automatically runs again within a specified period. For
example, on some controllers the Patrol Read runs every four hours and on other controllers, the Patrol Read runs every
seven days. The Patrol Read task runs continuously on the system starting again within the specified period after each
iteration of the task completes. If the system reboots while the Patrol Read task is running in Auto mode, the Patrol Read
restarts at zero percent (0%). When the Patrol Read task is set to Auto mode, you cannot start or stop the task. Auto
mode is the default setting.
NOTE:
For more information on how often the Patrol Read task runs when in Auto mode, see your controller
documentation.
Controllers 65