VERITAS Volume Manager 3.5 User's Guide - VERITAS Enterprise Administrator (September 2004)

Volume Tasks
Adding a Mirror to a Volume
Chapter 4 129
After you have provided all necessary information in the dialog box, click
OK. Adding a mirror requires resynchronization, so this task may take
some time.
NOTE
• The Mirror Add task requires a volume name.
• Once mirrored, the data in the volume is redundant. If a disk fails,
the data remains available on the surviving mirror (on another disk).
• The new mirror cannot be created on a disk that already contains a
copy of the volume. Each mirror must reside on a separate disk.
• Sufficient disk space must be available to accommodate the
additional mirrors.
• Only disks in the same disk group as the volume can be used to
create the new mirror.
• If no disks are assigned, VxVM uses available disk space to create
the mirror.
• A RAID-5 volume cannot be mirrored.
• If your system supports root volumes, then you can mirror the root
volume (and other volumes required to boot the system) onto an
alternate boot disk, use the Mirror Disk task.
• You require a licence to mirror disks other than the root disk.
• A volume can contain up to 32 plexes (mirrors).
• If you create more than one mirror at a time, you may see
inconsistent information on the progress bar. Also, the generation of
multiple mirrors does affect system resources. After creating a
mirror, you may want to wait until it has finished generating before
creating another mirror.