Users Guide

NOTE: To enable the automatic Replace Member, use the Dell OpenManage storage management application. For information on
manual Replace Member, see Replacing An Online Physical Disks.
Patrol Read
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 congured 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 congured 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.
• Patrol Read adjusts the amount of controller resources dedicated to Patrol Read operations based on outstanding disk I/O. For
example, if the system is busy processing I/O operation, then Patrol Read uses fewer resources to allow the I/O to take a higher
priority.
• Patrol Read does not run on any disks involved in any of the following operations:
– Rebuild
– Replace Member
– Full or Background Initialization
– CC
– RLM or OCE
NOTE
: By default, Patrol Read automatically runs every seven days on congured SAS and SATA hard
drives.
For more information on Patrol Read, see the Dell OpenManage documentation at Dell.com/openmanagemanuals.
Physical disk failure detection
Failed physical disks are detected and rebuilds automatically start to new disks that are inserted into the same slot. Automatic rebuilds can
also occur with hot spares. If you have congured hot spares, the controllers automatically try to use them to rebuild failed physical disks.
Using persistent hot spare slots
NOTE
: The persistent hot spare slot feature is disabled by default.
The PERC 10 series can be congured so that the system backplane or storage enclosure disk slots are dedicated as hot spare slots. This
feature can be enabled using the Dell OpenManage storage management application.
Once enabled, any slots with hot spares congured automatically become persistent hot spare slots. If a hot spare disk fails or is removed, a
replacement disk that is inserted into the same slot automatically becomes a hot spare with the same properties as the one it is replacing. If
the replacement disk does not match the disk protocol and technology, it does not become a hot spare.
For more information on persistent hot spares, see the Dell OpenManage documentation at Dell.com/openmanagemanuals.
Physical disk hot swapping
NOTE
: To check if the backplane supports hot swapping, see the Owner’s Manual of your system.
Features 35