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

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Volume group migration from Version 1.0 to Version 2.x
Using the vgversion command, you can convert a Version 1.0 volume group to any supported
2.x volume group, but a 2.x volume group cannot be migrated to a 1.0 volume group. See
Recovering from failures for information on how to undo the changes that were made by running the
vgversion command during the migration process.
If the volume group is deactivated, vgversion activates it in both the review option (-r) and during
the migration operation (-v). The vgversion command terminates if the volume group is active and
the review option is not used (this is necessary as vgversion must be in full control of the volume
group; it must be able to choose the options used to activate it, and have the ability to deactivate as
necessary). Then, vgversion calls vgcfgbackup to create the configuration backup file
corresponding to the initial configuration of the volume group. You can use this configuration backup
file to undo the changes performed by the vgversion command.
Change in the major number of the LV device special files
All the device special files (DSFs) that belong to a Version 1.0 volume group have the major number
64. All the DSFs that belong to a 2.x volume group have the major number 128. When a volume
group is migrated from Version 1.0 to 2.x, all DSFs under the /dev/vg_name volume group
directory are deleted and recreated with the new major number; the minor numbers remain the same.
The names of the DSFs are not altered during volume group migration.
Change in the minor number of the LV special DSFs
As the major number is changed, there might already be a Version 2.x volume group with the same
minor number or index number. In this case, the first unused minor number is used. When the minor
numbers do not clash, the same minor number is used. For example, assume that the current setup is
as follows:
# ll /dev/*/group
crw-r----- 1 root sys 64 0x000000 Jan 6 23:58 /dev/vg00/group
crw-r----- 1 root sys 64 0x010000 Jan 11 20:34 /dev/vg01/group
crw-r----- 1 root sys 128 0x000000 Jan 12 00:19 /dev/vg02/group
crw-r----- 1 root sys 128 0x001000 Jan 12 00:19 /dev/vg03/group
While converting vg01 from Version 1.0 to 2.x, minor number 2 is automatically assigned as minor
numbers 0 and 1 are in use by vg02 and vg03, respectively.
After conversion the output is as follows:
# ll /dev/*/group
crw-r----- 1 root sys 64 0x000000 Jan 6 23:58 /dev/vg00/group
crw-r----- 1 root sys 128 0x002000 Jan 12 22:38 /dev/vg01/group
crw-r----- 1 root sys 128 0x000000 Jan 12 00:19 /dev/vg02/group
crw-r----- 1 root sys 128 0x001000 Jan 12 00:19 /dev/vg03/group
Changes to /etc/lvmtab file
Configuration information about LVM Version 1.0 volume groups is stored in the /etc/lvmtab file;
Version 2.x volume group information is stored in the /etc/lvmtab_p file. When a volume group
is migrated from Version 1.0 to 2.x, the volume group entry is moved from /etc/lvmtab to
/etc/lvmtab_p.