Veritas Volume Manager 5.0 Migration Guide, HP-UX 11i v3, First Edition, May 2008

25Converting LVM to VxVM
Converting LVM volume groups to VxVM disk groups
This file provides information on how to proceed further to link the old LVM
volume names to the new VxVM device names.
Caution: This method of resolving the naming problem has risks. The symbolic
links can become stale. For example, if a database refers to
/dev/vx/rdsk/vol1
through a symbolic link
/dev/vg00/rvol1(“the old LVM name)”, and if the
underlying VxVM volume configuration is changed in any way, the database
could refer to a missing or different volume.
Note: You may want to use this symbolic link approach to ease the transition to
VxVM. You can set up the symbolic links after the successful conversion to
VxVM. Then, you can do the investigation on a case by case basis for each
volume. Once you are satisfied that there are no problems introduced by the
name change, the symbolic link to that volume can be removed. You must be
careful to maintain a static VxVM volume configuration during this transition
period.
Over time, the ultimate goal should be that the underlying VxVM naming is used
by all applications, and that there are no indirect references to those volumes.
6. Stopping application access to volumes in the volume
group to be converted
No applications can be active on the LVM volume group undergoing conversion.
Before attempting to convert any volume group, you must ensure that
applications using that group are down. This involves stopping databases,
unmounting file systems, etc.
Note: If you are converting a volume with swap space on it, the conversion
requires a reboot. The swap space cannot be taken out of control of the
operating system with a shutdown to single user mode.
As described in “Conversion and reboot” on page 26,
vxvmconvert tries to
unmount mounted file systems during the conversion. Bear in mind though,
that
vxvmconvert makes no attempt to close down running applications on
those file systems, nor does it attempt to deal with applications (e.g., databases)
running on raw LVM volumes.