VERITAS Volume Manager 5.0 Migration Guide (September 2006)

29Converting LVM to VxVM
Restoring the LVM volume group configuration
The name changes that vxvmconvert makes as part of the conversion are managed by
rollback, and do not count as VxVM configuration changes for the purposes of choosing a
restoration method.
The
vgrestore command should not be confused with the LVM command,
vgcfgrestore. vgcfgrestore is used to restore the LVM configuration information
saved by
vgcfgbackup, but it will not restore your device files and/etc/fstab entries.
It also will not import and activate the volume group, nor will it clean up any VxVM
information left around. However, vgrestore will do all of this for you.
Rollback to LVM using vxvmconvert
Rollback replaces the VxVM disk groups with the original LVM volume groups. During
conversion, vxvmconvert saves a “snapshot” of the original LVM metadata and associated
configuration files, such as /etc/fstab and LVM device files. It restores only the LVM
metadata and configuration files from this snapshot; user data is not changed. This method
can only be used if no changes have been made to the configuration since the conversion.
For example, if a disk has been added to the disk group or if the names of any logical
volumes have changed, you cannot use the rollback method.
Note: In many cases, if you choose the rollback method and the configuration has
changed, you receive an error and must use the full restore method.
If you used the workaround of creating symbolic links from the old LVM names to the
new VxVM names described in “step 5. Planning for new VxVM logical volume names,”
you must remove the symbolic links you created before beginning the rollback.
This “snapshot” is kept on the root file system. The presence of this snapshot should not
be taken as assurance that full off-line backups will not be needed. See “4. Backing up
your LVM configuration and user data” for specific information on backups.
To rollback to LVM from the VxVM conversion, run
vxvmconvert and choose option 3.
See “Example: VxVM to LVM rollback” on page 42 for illustration.