VERITAS Volume Manager 5.0 Migration Guide (September 2006)

22 Converting LVM to VxVM
Converting LVM volume groups to VxVM disk groups
Sample examples of the analyze option are shown in “Examples” on page 31.
3. Taking actions to make conversion possible if analysis fails
Analysis may fail for any of the reasons listed in the section “Volume group conversion
limitations”.
Messages from vxvmconvert will explain the type of failure and any actions that can be
taken before retrying the analysis. Refer to “Conversion error messages” on page 71 for
complete details of specific error messages and actions.
4. Backing up your LVM configuration and user data
After analysis you know which volume group or groups you want to convert to VxVM
disk groups. Up to this point, you have not altered your LVM configuration.
By taking the next step (completing the conversion to VxVM), you are significantly
changing access to your storage.
Although the conversion process does not move, or in any other way affect user data, you
are strongly encouraged to back up all data on the affected disks. Similarly, you should
back up the LVM configuration itself.
During a conversion, any spurious reboots, power outages, hardware errors or operating
system bugs can have unpredictable and undesirable consequences. You are advised to be
on guard against disaster with a set of verified backups.
Backing up an LVM configuration
Use the vgcfgbackup(1M) utility before running vxvmconvert to save a copy of the
LVM configuration.
You can back up the LVM volumes using the following command:
# vgcfgbackup -f pathname/filename vol_grp_name
Be sure to use the -f option to save the data into a file other than the default.
vxvmconvert uses LVM utilities which themselves save the configuration using
vgcfgbackup. If you do not use the -f option when you attempt to backup the
configuration, the conversion process will overwrite your attempted backup.
A copy of this LVM configuration should be kept off-line on tape or some other medium
for use in the event of a disaster during conversion.
For example, to put a copy on tape, use the following command:
# tar cvf /dev/rmt/c3t0d0BEST /vgbackups/vg08