VERITAS Volume Manager 3.5 Migration Guide (August 2002)

Chapter 2, Converting LVM to VxVM

Final 24 July 2002 Restoring the LVM Volume Group Configuration

Note You must only rename objects in the VxVM conﬁguration after you are fully

satisﬁed with that conﬁguration. In particular, you should never use menu option 3

of vxvmconvert (Roll back) after name changes. If you have chosen to set up

symbolic links to the VxVM volumes as described in “step 5. Planning for new

VxVM logical volumenames,” avoidrenamingVxVM objects.These symboliclinks

are made invalid if the underlying VxVM device node name changes.

Restoring the LVM Volume Group Conﬁguration

In some circumstances, you mayneed to restorethe LVM conﬁgurationthat 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 22 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 thenrestoresthe original userdatafromthe backup that wasmade

before the conversion was done (frecover). See “Full LVM Restoration” on page 23

for more information on using this method.