Moving Volume Group From One Lpar To Another Lapar

Remove a volume group from the source LPAR :

When you have your data ready to move, remove the volume group and its physical volumes from the source LPAR. To do that, the logical volumes belonging to that volume group must be closed. That requires you to unmount the file systems that belong to the volume group you are going to export.

List file systems in the volume group

To identify the file systems belonging to a volume group, use the lsvgfs command:

# lsvgfs sparevg # /scratch

Unmount file systems

Unmount any file systems in the volume group using the umount command:

# umount /scratch

You also need to deactivate any paging spaces and de-configure any system dump devices that belong to the volume group (see resources  for details).

When the logical volumes are closed, you should be able to deactivate the volume group.

Deactivate the volume group

You can make the volume group inactive with the varyoffvg command:

# varyoffvg sparevg

You can check the volume group status by listing physical volumes with lspv. This shows the volume group name. The volume group status is no longer listed as active.

# lspv # hdisk0          00cb07a4cee0b389                    rootvg          active # hdisk1          00cb07a42fb87e1d                    sparevg

Export the volume group

You should now be able to export the volume group using exportvg:

# exportvg sparevg

After you run exportvg, lspv displays the volume group as None:

# lspv # hdisk0          00cb07a4cee0b389                    rootvg          active # hdisk1          00cb07a42fb87e1d                    None

You could import the volume group again on the source LPAR using importvg. However, because you're planning to move it to another LPAR, you need to remove the references to the disks from the operating system on the source LPAR.

Remove the physical volumes from the ODM

The ODM still keeps a record of the physical volumes at the operating system level. It is now safe to delete the physical volumes belonging to the volume group using rmdev. This removes references to the disks on the source LPAR, but it doesn't affect the data on the disks.

Volume group descriptor area and volume group status area

Each of the disks in the volume group has management data, including a volume group descriptor area and a volume group status area. This management data is stored on each physical volume of the volume group. When you remove the disks from the ODM, the disk management data remains intact.

# rmdev -d -l hdisk1 # hdisk1 deleted

Assign storage to target LPAR

The next step is to assign the storage to the target LPAR. How you do this depends on your storage configuration. Whoever is responsible for your storage subsystem should be able to present the disks to the new LPAR.

Import data on target LPAR

After you assign the disks to the target LPAR, you need to identify them at the operating system level and then make the volume group and file systems available.

Identify new disks on target LPAR

The new disks need to be discovered on the operating system of the target LPAR. A reboot of the LPAR would do this, but that's not necessary. You can run cfgmgr to configure the new devices:

# cfgmgr

The lspv command should show these disks with their Physical Volume Identifier (PVID). The volume group is shown as None, and the volume group status doesn't display as active.

# lspv # hdisk0          00cb07a4b24eb714                    rootvg          active # hdisk1          00cb07a42fb87e1d                    None

The disk name on the target LPAR (hdiskN) may not be the same name as the source LPAR. However, the PVID should be the same on the source and the target because it is a unique identifier for each physical volume.

Import the volume group on the target LPAR

Use the importvg command and a PhysicalVolume parameter to import the volume group. You only need to specify one physical volume, even if there are several physical volumes in the volume group. The importvg command finds any remaining physical volumes belonging to the same volume group and includes them in the import.

# importvg -y sparevg hdisk1

The system automatically runs the varyonvg command to activate the volume group after it is imported. If the volume group is concurrent capable, you will be prompted by the importvg command to activate the imported volume group manually usingvaryonvg.

Updating file systems

If the volume group has file systems in it, the /etc/filesystems file is updated with information for the imported volume group's logical volumes and mount points. This saves you rebuilding the logical volumes and file systems yourself, as you would need to do before running a traditional restore or copy operation. The logical volume and file system characteristics are also inherited.

Before mounting the file systems, you need to verify their integrity.

Run fsck on all file systems

You should check the file system consistency for each file system. You can do this with the fsck command:

# fsck /scratch

Mount the file systems on target LPAR

You are now ready to mount the file systems, check permissions, and verify the file system contents. Once again, you can list all the file systems belonging to the volume group with lsvgfs. The mount command makes the file system available, along with all of its contents.

# mount /scratch

You can check the mounted file systems using df. Be sure to check the permissions on the mount points, directories, and files.