Veritas Volume Manager 5.0 Troubleshooting Guide Guide (September 2006)

Chapter
1
Recovery from hardware
failure
Symantec’s Veritas Volume Manager (VxVM) protects systems from disk and other
hardware failures and helps you to recover from such events. This chapter describes
recovery procedures and information to help you prevent loss of data or system access due
to disk and other hardware failures.
If a volume has a disk I/O failure (for example, because the disk has an uncorrectable
error), 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
“Administering Hot-Relocation” chapter in the Veritas Volume Manager Administrator’s
Guide.
Recovery from failures of the boot (root) disk requires the use of the special procedures
described in “Recovery from boot disk failure” on page 35.