VERITAS Volume Manager 3.5 Migration Guide (August 2002)

Chapter 2, Converting LVM to VxVM
Final 24 July 2002 Converting LVM Volume Groups to VxVM Disk Groups
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Unlike LVM, VxVM does not support bad block revectoring at the physical volume
level. If there appear to be any valid bad blocks in the bad block directory of any disk
used in an LVM volumegroup, the group cannot be converted. See Appendix A,
Conversion Error Messages, for actions to take in this situation.
◆ Not enough disk space on the root file system to save a copy of each physical disk’s
LVM metadata.
For large volume groups, for example, 200 GB using approximately twenty 9GB
drives, the space needed could be as much as 30 MB.
◆ Volume groups with mirrored volumes.
A conversion fails if the LVM volume group being converted has mirrored volumes,
but the system does not have a valid license installed that enables mirroring for
VxVM.
The analyze option in vxvmconvert, which is described in later sections, aids you in
identifying which volume groups can be converted.
Conversion Process Summary
Several steps are used to convert LVM volume groups to VxVM disk groups. Most of
these steps can be done with the vxvmconvert utility. All the steps are not compulsory,
and some may have to be followed only if there are problems during conversion. Some of
them (e.g. backing up user data) are left to you to accomplish through your regular
administrative processes.
The steps in the conversion process are:
1. Identifying LVM volume groups for conversion.
2. Analyzing an LVM group to see if conversion is possible.
3. Taking actions to make conversion possible if analysis fails.
4. Backing up your LVM configuration and user data.
5. Planning for new VxVM logical volume names.
6. Stopping application access to volumes in the volume group to be converted.
7. Converting a volume group.
8. Taking actions if conversion fails.
9. Implementing changes for new VxVM logical volume names