VERITAS Volume Manager 3.5 Migration Guide (August 2002)

Restoring the LVM Volume Group Configuration Final 24 July 2002

22 VERITAS Volume Manager Migration Guide

Note Restoring user data using the vgrestore and frecover method will result in the

loss of all user data changes made since the conversion, and the loss of all new

volumes created since the conversion.

In other words, this method of restoring data will take you back to exactly where

you were before the conversion was done.

However, ifno new volumes havebeen created,and if none of the existing volumes

have been resized, you can use the vxvmconvert rollback option to restore the

original LVM conﬁguration. If you use this method, any user data changes made

since the conversion will be retained, and you will not need to carry out a user level

data restore (frecover).

Note The namechanges thatvxvmconvert makes as partof theconversion aremanaged

by rollback, and do not count as VxVM conﬁguration changes for the purposes of

choosing a restoration method.

Note vgrestore (1M) should notbeconfused with the LVM command,vgcfgrestore

(1M). vgcfgrestore is used to restore the LVM conﬁguration information saved

by vgcfgbackup (1M), 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” ofthe originalLVMmetadata 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.