VERITAS Volume Manager 4.1 Administrator's Guide

Administering Hot-Relocation
Introduction
Chapter 9326
Introduction
If a volume has a disk I/O failure (for example, because the disk has an
uncorrectable error), Volume Manager (VxVM) can detach the plex
involved in the failure. I/O stops on that plex but continues on the
remaining plexes of the volume.
If a disk fails completely, VxVM can detach the disk from its disk group.
All plexes on the disk are disabled. If there are any unmirrored volumes
on a disk when it is detached, those volumes are also disabled.
NOTE Apparent disk failure may not be due to a fault in the physical disk
media or the disk controller, but may instead be caused by a fault in an
intermediate or ancillary component such as a cable, host bus adapter, or
power supply.
The hot-relocation feature in VxVM automatically detects disk failures,
and notifies the system administrator and other nominated users of the
failures by electronic mail. Hot-relocation also attempts to use spare
disks and free disk space to restore redundancy and to preserve access to
mirrored and RAID-5 volumes. For more information, see the following
section, “How Hot-Relocation works” on page 327
If hot-relocation is disabled or you miss the electronic mail, you can use
the vxprint command or the graphical user interface to examine the
status of the disks. You may also see driver error messages on the console
or in the system messages file.
Failed disks must be removed and replaced manually as described in
“Removing and Replacing Disks” on page 97.
For more information about recovering volumes and their data after
hardware failure, see the VERITAS Volume Manager Troubleshooting
Guide.