HP-UX 11i v3 - LVM Volume Group Version Migration (September 2010)

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Migration of volume group with bootable physical volumes
Beginning with the HP-UX 11i v3 March 2010 Update release, Version 2.2 volume groups and 1.0
volume groups support bootable physical volumes. Version 2.0 and 2.1 volume groups do not
support bootable physical volumes. Although migration from Version 1.0 to 2.x volume groups
(particularly to 2.2, which supports bootable physical volume) and from Version 2.2 to 2.x volume
groups is possible, vgversion does not support the migration if the volume group has bootable
physical volumes. If you do not need a bootable volume group, use vgmodify –B n and convert all
bootable physical volumes to nonbootable physical volumes. Then, retry volume group migration.
Unsupported features in Version 2.x volume groups
The following features are supported in Version 1.0 volume groups, but are not supported by
2.x volume groups:
Spare physical volumes
Bad block relocation
If a Version1.0 volume group has a physical volume that is marked as a spare physical volume, the
volume group cannot be migrated. You must change all spare physical volumes to regular physical
volumes using pvchange –z n.
If any of the physical volumes belonging to a Version 1.0 volume group have relocated bad blocks,
using vgversion fails. You cannot migrate this volume group Version 2.x.
A physical volume belonging to a Version 2.x volume group must not have any relocated bad blocks.
If any physical volume has relocated bad blocks, you must replace that physical volume with a new
disk. For more information on how to replace a disk, see the When good disks go bad: Dealing with
disk failures under LVM white paper.
By default, bad block relocation for all logical volumes of a Version 2.x volume group is set to NONE.
For more information, see the –r option in lvchange(1M). When a Version 1.0 volume group is
migrated to 2.x, the bad block relocation option for all logical volumes is automatically
set to NONE.
–U option support for migration to Version 2.2 volume groups
To support snapshots, a new configuration parameter called the unshare unit is introduced for
Version 2.2 volume groups. It is the smallest unit for which data can be unshared between a logical
volume and its snapshots. You can configure the unshare unit only during creation of volume group or
during migration to a Version 2.2 volume group.
A new option -U is introduced to choose the unshare unit while migrating to a Version 2.2 volume
group. The –U option sets the unit at which data will be unshared between a logical volume and its
snapshots. The supported values are 512 KB, 1024 KB, 2048 KB, and 4096 KB. If you do not use
the –U option when migrating to 2.2 volume group, the unshare unit is set to the default value of
1024 KB. After this value is set, you cannot change it. The unshare unit cannot be greater than the
size of the physical extent of the volume group.
For more information on the unshared unit, see the Using LVM logical volume snapshots white paper.