VERITAS Volume Manager 3.5 Administrator's Guide (September 2004)

Creating and Administering Disk Groups
Upgrading a Disk Group
Chapter 4170
Upgrading a Disk Group
NOTE This information is not applicable for platforms whose first release was
Volume Manager 3.0. However, it is applicable for subsequent releases.
Prior to the release of Volume Manager 3.0, the disk group version was
automatically upgraded (if needed) when the disk group was imported.
From release 3.0 of Volume Manager, the two operations of importing a
disk group and upgrading its version are separate. You can import a disk
group from a previous version and use it without upgrading it.
When you want to use new features, the disk group can be upgraded. The
upgrade is an explicit operation. Once the upgrade occurs, the disk group
becomes incompatible with earlier releases of VxVM that do not support
the new version.
Before the imported disk group is upgraded, no changes are made to the
disk group to prevent its use on the release from which it was imported
until you explicitly upgrade it to the current release.
Until completion of the upgrade, the disk group can be used “as is”
provided there is no attempt to use the features of the current version.
Attempts to use a feature of the current version that is not a feature of
the version from which the disk group was imported results in an error
message similar to this:
vxvm:vxedit: ERROR: Disk group version doesn’t support feature
To use any of the new features, you must run the vxdg upgrade command
to explicitly upgrade the disk group to a version that supports those
features.
All disk groups have a version number associated with them. Volume
Manager releases support a specific set of disk group versions. VxVM can
import and perform operations on a disk group of that version. The
operations are limited by what features and operations the disk group
version supports.