Users Guide

Table 20. Memory channels (continued)
Property Definition
Dedicated Hot Spare Displays whether the foreign disk is a dedicated hot spare.
Based on the properties information, you can decide whether you want to import, recover, or clear the foreign configuration.
Viewing Patrol Read report
The patrol read report provides information on all the patrol reads performed on the controller in the chronological order. It provides
information such as last run time and result. If a patrol read fails, the reason for the failure is displayed.
Setting Patrol Read mode
NOTE: This task is not supported on PERC hardware controllers running in HBA mode.
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 the disk errors, when possible. When the Set Patrol Read mode is set to
Auto, patrol read is initiated when the controller is idle for a specific 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 no 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 is suspended during heavy I/O activity and resumes when the I/O is finished.
To set 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.
Manual — Enables you to start and stop the Patrol Read task using Start and Stop Patrol Read. Setting the mode to Manual does
not initiate the Patrol Read task. If the system reboots while Patrol Read is running in Manual mode, Patrol Read does not restart.
Disabled — Prevents the Patrol Read task from running on the system.
To set 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.
Manual — Enables you to start and stop the Patrol Read task using Start and Stop Patrol Read. Setting the mode to Manual does
not initiate the Patrol Read task. If the system reboots while Patrol Read is running in Manual mode, Patrol Read does not restart.
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Troubleshooting hardware issues