VERITAS Volume Manager 3.5 Troubleshooting Guide (September 2004)

Recovery from Hardware Failure
Introduction
Chapter 1
10
Introduction
Veritas 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 Chapter 2, “Recovery from Boot Disk Failure,” on page 29.