VERITAS Volume Manager 3.5 Migration Guide (September 2004)

Chapter 2

Converting LVM to VxVM

Restoring the LVM Volume Group Conﬁguration

In some circumstances, you may need to restore the LVM conﬁguration that existed before you converted to

VxVM with vxvmconvert. For example:

• If something went wrong during the conversion, such as a system crash or a disk crash that caused the

conversion to be unworkable.

• If during a conversion only some of a set of volume groups converted successfully, then you may want to

restore the LVM conﬁguration for the entire set.

It is possible to restore the original LVM conﬁguration in one of two ways, but both have limitations and

restrictions. The method you use depends on if any changes have been made to the VxVM conﬁguration since

the conversion occurred. Any of the following actions changes the VxVM conﬁguration:

• adding or removing disks

• adding or removing volume groups

• changing the names of VxVM objects

Restoration methods include:

• rollback using vxvmconvert

Use rollback only if the VxVM conﬁguration has not changed since the conversion. This method restores

the LVM conﬁguration without the need for user data restoration. See “Rollback to LVM Using

vxvmconvert” on page 20 for details on using this method.

• restore user data using vgrestore and frecover

This method is a full LVM restoration which is used to restore your user data from backup when the

VxVM conﬁguration has changed since the conversion was made. First of all, this method restores the

original LVM conﬁguration information (vgrestore), and then restores the original user data from the

backup that was made before the conversion was done (frecover). See “Full LVM Restoration” on page 20

for more information on using this method.

NOTE Restoring user data using the vgrestore and frecover methods will result in the loss of

all user data changes made since the conversion, and the loss of all new volumes 0created

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, if no new volumes have been 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 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.