VERITAS Volume Manager 4.1 Administrator's Guide

Administering Volumes

Backing up Volumes Online

Chapter 8314

To snapshot all the volumes in a single disk group, specify the option -o

allvols to vxassist:

# vxassist -g diskgroup -o allvols snapshot

This operation requires that all snapstart operations are complete on the

volumes. It fails if any of the volumes in the disk group do not have a

complete snapshot plex in the SNAPDONE state.

Merging a Snapshot Volume (snapback)

NOTE The information in this section does not apply to RAID-5 volumes unless

they have been converted to a special layered volume layout by the

addition of a DCO and DCO volume. See “Attaching a DCO and DCO

volume to a RAID-5 Volume” on page 279 for details.

Snapback merges a snapshot copy of a volume with the original volume.

One or more snapshot plexes are detached from the snapshot volume and

re-attached to the original volume. The snapshot volume is removed if all

its snapshot plexes are snapped back. This task resynchronizes the data

in the volume so that the plexes are consistent.

NOTE To enhance the efﬁciency of the snapback operation, enable FastResync

on the volume before taking the snapshot, as described in “Enabling

FastResync on a Volume” on page 298.

To merge one snapshot plex with the original volume, use the following

command:

# vxassist snapback snapshot

where snapshot is the snapshot copy of the volume.

To merge all snapshot plexes in the snapshot volume with the original

volume, use the following command:

# vxassist -o allplexes snapback snapshot

To merge a speciﬁed number of plexes from the snapshot volume with

the original volume, use the following command:

# vxassist snapback nmirror=number snapshot