Dell PowerEdge RAID Controller H800 - Manual (Page 38)

38 Storage Controller Features
Battery Learn Cycle
Learn cycle is a battery calibration operation performed by the controller
periodically to determine the condition of the battery. This operation
cannot be disabled.
NOTE: Virtual disks automatically switch to Write-Through mode when the battery
charge is low because of a learn cycle.
Learn Cycle Completion Time Frame
The time frame for completion of a learn cycle is a function of the battery
charge capacity and the discharge/charge currents used. For PERC H700 or
H800 cards, the expected time frame for completion of a learn cycle is
approximately seven hours and consists of the following parts:
• Learn cycle discharge: approximately three hours
• Learn cycle charge: approximately four hours
NOTE: For additional information, see the Dell OpenManage storage management
application.
During the discharge phase of a learn cycle, the PERC H700 or H800 battery
charger is disabled and remains disabled until the battery is discharged.
After the battery is discharged, the charger is re-enabled.
Patrol Read
The Patrol Read feature is designed as a preventative measure to ensure
physical disk health and data integrity. Patrol Read scans for and resolves
potential problems on configured physical disks. The Dell OpenManage
storage management application can be used to start Patrol Read and
change its behavior.
The following is an overview of Patrol Read behavior:
• Patrol Read runs on all disks on the controller that are configured as
part of a virtual disk, including hot spares.
• Patrol Read does not run on physical disks that are not part of a virtual disk
or are in Ready state.
PERC7.2_UG.book Page 38 Thursday, March 3, 2011 2:14 PM