VERITAS Volume Manager 5.0 Migration Guide (September 2006)

30 Converting LVM to VxVM
Restoring the LVM volume group configuration
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 30 for specific information.
Full LVM restoration
If you need to restore the original LVM configuration, but changes have been made to the
VxVM configuration, you cannot use the rollback option of
vxvmconvert. In this case,
you must restore the user data in addition to restoring the old LVM metadata and
associated configuration files. You may need to use this method if the disks in use by the
LVM/VxVM volumes were corrupted during or after conversion.
Note: The snapshot of LVM internal data is kept on the root filesystem.
To use this method, you must have backed up data located on all the volume groups’
logical volumes before conversion to VxVM.
Restoration of LVM volume groups is a two-step process consisting of a restoration of
LVM internal data (metadata and configuration files), and restoration of user or
application data.
The process is limited to restoring the state of the logical volumes as they existed prior to
conversion to VxVM disks. If the data has changed on the volumes during the time they
were VxVM volumes, those changes are lost once you restore the LVM configuration and
saved user data.
To do a full restoration of the original LVM configuration, do the following:
1Use
vgrestore to restore LVM internal data.
# vgrestore vol_grp_name
2 Use the recovery method to restore user or application data. In preparation for
conversion, the recovery method should have been done with the standard backups
you made in preparation for conversion. The following example shows an
frecover
from the
fbackup example in “step 4. Backing up your LVM configuration and user
data.”
# mount -F vxfs /dev/vg01/lvol3 /foodir
# frecover -r -f /dev/rmt/c0t0d0BEST