280Administering volumes

Upgrading existing volumes to use version 20 DCOs

#vxdg list diskgroup

To upgrade a disk group to the latest version, use the following command:

#vxdg upgrade diskgroup

For more information, see “Upgrading a disk group” on page 208.

2Use the following command to discover which volumes in the disk group have version 0 DCOs associated with them:

#vxprint [-g diskgroup] -F “%name” -e “v_hasdcolog”

Note: This command assumes that the volumes can only have version 0 DCOs as the disk group has just been upgraded. See “Determining the DCO version number” on page 277 for a description of how to find out the DCO version number of a volume in any disk group.

Repeat the following steps to upgrade each volume within the disk group as required.

3If the volume to be upgraded has a traditional DRL plex or subdisk (that is, the DRL logs are not held in a version 20 DCO volume), use the following command to remove this:

#vxassist [-g diskgroup] remove log volume [nlog=n]

Use the optional attribute nlog=n to specify the number, n, of logs to be removed. By default, the vxassist command removes one log.

4For a volume that has one or more associated snapshot volumes, use the following command to reattach and resynchronize each snapshot:

#vxassist [-g diskgroup] snapback snapvol

If FastResync was enabled on the volume before the snapshot was taken, the data in the snapshot plexes is quickly resynchronized from the original volume. If FastResync was not enabled, a full resynchronization is performed.

5Use the following command to turn off FastResync for the volume:#vxvol [-g diskgroup] set fastresync=off volume

6Use the following command to dissociate a version 0 DCO object, DCO volume and snap objects from the volume:

#vxassist [-g diskgroup] remove log volume logtype=dco7Use the following command on the volume to upgrade it:

#vxsnap [-g diskgroup] prepare volume [ndcomirs=number] \ [regionsize=size] [drl=onsequentialoff] \ [storage_attribute ...]

The ndcomirs attribute specifies the number of DCO plexes that are created in the DCO volume. It is recommended that you configure as many DCO plexes as there are data and snapshot plexes in the volume. The DCO plexes are used to set up a DCO volume for any snapshot volume that you