To move a whole volume group from one system to another, the vgexport and vgimport commands can be used. Below example involves the steps to move a volume group named “data_vg” from one system to another. The logical volume from this volume group is initially mounted at /data01.
1. Un-mount the file system
If required switch to “rescue” mode. Make sure that no users are accessing files on the active volume.
# umount /data01
2. Mark the volume group inactive
Marking the volume group inactive removes it from the kernel and prevents any further activity on it.
# vgchange -an data_vg vgchange -- volume group "data_vg" successfully deactivated
3. Export the volume group
This prevents it from being accessed on the “old” host system and prepares it to be removed.
# vgexport data_vg vgexport -- volume group "data_vg" successfully exported
4. Un-present the Disk
Once the Disk has been unplugged from the server, it can be shutdown. The Disk can now be presented to the new Server on which VG data_vg has to be discovered.
5. Present the Disk to the new Server
When plugged into the new system it becomes /dev/sdb so an initial pvscan shows as below:
# pvscan pvscan -- reading all physical volumes (this may take a while...) pvscan -- inactive PV "/dev/sdb1" is in EXPORTED VG "data_vg" [996 MB / 996 MB free] pvscan -- inactive PV "/dev/sdb2" is in EXPORTED VG "data_vg" [996 MB / 244 MB free] pvscan -- total: 2 [1.95 GB] / in use: 2 [1.95 GB] / in no VG: 0 [0]
6. Import the Volume Group
If importing on an LVM 2 system, run below command:
# vgimport data_vg Volume group "data_vg" successfully imported
Else if importing on an LVM system, add the PVs that need to be imported:
# vgimport data_vg /dev/sdb1 /dev/sdb2 vgimport -- doing automatic backup of volume group "data_vg" vgimport -- volume group "data_vg" successfully imported and activated
7. Activate the volume group
# vgchange -ay data_vg
8. Mount the file system
# mkdir -p /data01 # mount /dev/data_vg/lv_data01 /data01