VERITAS Volume Manager 4.1 Migration Guide
Converting LVM to VxVM
Restoring the LVM Volume Group Configuration
Chapter 2 15
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 “5. Planning for new VxVM logical
volume names” on page 11, 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” on page 9 for specific
information on backups.
To rollback to LVM from the VxVM conversion, run vxvmconvert and choose option 3. See
“Examples” on page 20 for illustration.
CAUTION Do not use this option unless you are certain that you want to restore LVM
volume groups. Once this is run, the VxVM disks that were created as a result
of the original conversion from LVM to VxVM no longer exists. This option is
not a full complement to vxvmconvert. It simply writes the saved LVM
metadata back on top of the disks. Those data can only be considered valid for
the period of time when the logical volumes are off-line. If the VxVM
configuration has been brought online, the metadata in the rollback snapshot
should be considered obsolete. See “Full LVM Restoration” on page 18 for
specific information.