Dell PowerEdge RAID Controller 12 User’s Guide PERC H965i Adapter, PERC H965i Front, PERC H965i MX, and PERC H965e Adapter

The Patrol read feature is designed as a preventative measure to ensure physical disk health and data integrity. Patrol read scans 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.

Some properties of the patrol-read feature are:

• Runs on all disks on the controller that are configured as part of a virtual disk, including hot-spares.
• The Patrol read feature does not run on physical disks that are not part of non-RAID disks, virtual disks, or drives that are in Ready state.
• The amount of controller resources dedicated to patrol read operations adjusts based on the number of outstanding disk I/O operations. For example, if the system is processing a large number of I/O operations, then patrol read uses fewer resources to allow the I/O to take a higher priority.
• Patrol read does not run on disks that are involved in any of the following operations:
  • Rebuild
  • Replace member
  • Full or background initialization
  • Consistency Check
  • Online capacity expansion (OCE)
  NOTE:By default, patrol read automatically runs every seven days on configured hard drives.

For more information about patrol read, see the Dell OpenManage Storage Management User's Guide available at OpenManage Manuals.