VERITAS Volume Manager 3.1 Administrator's Guide

Volume Tasks
Moving Subdisks
Chapter 6 277
Moving Subdisks
Moving a subdisk copies the disk space contents of a subdisk onto
another subdisk. If the subdisk being moved is associated with a plex,
then the data stored on the original subdisk is copied to the new subdisk.
The old subdisk is dissociated from the plex, and the new subdisk is
associated with the plex. The association is at the same offset within the
plex as the source subdisk. To move a subdisk, use the following
command:
# vxsd mv old_subdisk_name new_subdisk_name
For the subdisk move task to work correctly, the following conditions
must be met:
• The subdisks involved must be the same size.
• The subdisk being moved must be part of an active plex on an active
(ENABLED) volume.
• The new subdisk must not be associated with any other plex.
Moving Relocated Subdisks
When hot-relocation occurs, subdisks are relocated to spare disks and/or
available free space within the disk group. The new subdisk locations
may not provide the same performance or data layout that existed before
hot-relocation took place. Move the relocated subdisks (after
hot-relocation is complete) to improve performance.
You can also move the relocated subdisks off the spare disk(s) to keep the
spare disk space free for future hot-relocation needs. Another reason for
moving subdisks is to recreate the configuration that existed before
hot-relocation occurred.
During hot-relocation, one of the electronic mail messages sent to root is
shown in the following example:
To: root
Subject: Volume Manager failures on host teal
Attempting to relocate subdisk disk02-03 from plex
home-02.
Dev_offset 0 length 1164 dm_name disk02 da_name
c0t5d0s2.