VERITAS Volume Manager 3.1 Administrator's Guide

Recovery
RAID-5 Recovery
Chapter 8372
RAID-5 Recovery
NOTE You may need an additional license to use this feature.
Here are the types of recovery typically needed for RAID-5 volumes:
• parity resynchronization
• stale subdisk recovery
• log plex recovery
These types of recovery are described in the sections that follow. Parity
resynchronization and stale subdisk recovery are typically performed
when:
• the RAID-5 volume is started
• shortly after the system boots
• by calling the vxrecover command
For more information on starting RAID-5 volumes, see “Starting RAID-5
Volumes”.
If hot-relocation is enabled at the time of a disk failure, system
administrator intervention is not required unless there is no suitable
disk space available for relocation. Hot-relocation is triggered by the
failure and the system administrator is notified of the failure by
electronic mail.
Hot-relocation automatically attempts to relocate the subdisks of a
failing RAID-5 plex. After any relocation takes place, the hot-relocation
daemon (vxrelocd) also initiate a parity resynchronization.
In the case of a failing RAID-5 log plex, relocation only occurs if the log
plex is mirrored; the vxrelocd daemon then initiates a mirror
resynchronization to recreate the RAID-5 log plex. If hot-relocation is
disabled at the time of a failure, the system administrator may need to
initiate a resynchronization or recovery.