Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

383Administering hot-relocation
Moving and unrelocating subdisks
Moving hot-relocated subdisks back to a different disk
The vxunreloc utility provides the -n option to move the subdisks to a different disk
from where they were originally relocated.
Assume that mydg01 failed, and that all of the subdisks that resided on it were
hot-relocated to other disks. vxunreloc provides an option to move the subdisks to a
different disk from where they were originally relocated. After the disk is repaired, it is
added back to the disk group using a different name, for example, mydg05. If you want to
move all the hot-relocated subdisks back to the new disk, the following command can be
used:
# vxunreloc -g mydg -n mydg05 mydg01
The destination disk should have at least as much storage capacity as was in use on the
original disk. If there is not enough space, the unrelocate operation will fail and none of
the subdisks will be moved.
Forcing hot-relocated subdisks to accept different offsets
By default, vxunreloc attempts to move hot-relocated subdisks to their original offsets.
However,
vxunreloc fails if any subdisks already occupy part or all of the area on the
destination disk. In such a case, you have two choices:
■ Move the existing subdisks somewhere else, and then re-run vxunreloc.
■ Use the -f option provided by vxunreloc to move the subdisks to the destination
disk, but leave it to vxunreloc to find the space on the disk. As long as the
destination disk is large enough so that the region of the disk for storing subdisks can
accommodate all subdisks, all the hot-relocated subdisks will be unrelocated without
using the original offsets.
Assume that mydg01 failed and the subdisks were relocated and that you want to move
the hot-relocated subdisks to mydg05 where some subdisks already reside. You can use
the force option to move the hot-relocated subdisks to mydg05, but not to the exact
offsets:
# vxunreloc -g mydg -f -n mydg05 mydg01
Examining which subdisks were hot-relocated from a disk
If a subdisk was hot relocated more than once due to multiple disk failures, it can still be
unrelocated back to its original location. For instance, if mydg01 failed and a subdisk
named mydg01-01 was moved to mydg02, and then mydg02 experienced disk failure,
all of the subdisks residing on it, including the one which was hot-relocated to it, will be
moved again. When mydg02 was replaced, a
vxunreloc operation for mydg02 will do
nothing to the hot-relocated subdisk mydg01-01. However, a replacement of mydg01
followed by a
vxunreloc operation, moves mydg01-01 back to mydg01 if vxunreloc
is run immediately after the replacement.