Veritas Volume Manager 5.0.1 Administrator's Guide, HP-UX 11i v3, First Edition, November 2009

Note: If the snapstart procedure is interrupted, the snapshot mirror is
automatically removed when the volume is started.
Once the snapshot mirror is synchronized, it continues being updated until it is
detached. You can then select a convenient time at which to create a snapshot
volume as an image of the existing volume. You can also ask users to refrain from
using the system during the brief time required to perform the snapshot (typically
less than a minute). The amount of time involved in creating the snapshot mirror
is long in contrast to the brief amount of time that it takes to create the snapshot
volume.
The online backup procedure is completed by running the vxassist snapshot
command on a volume with a SNAPDONE mirror. This task detaches the finished
snapshot (which becomes a normal mirror), creates a new normal volume and
attaches the snapshot mirror to the snapshot volume. The snapshot then becomes
a normal, functioning volume and the state of the snapshot is set to ACTIVE.
397Administering volume snapshots
Creating traditional third-mirror break-off snapshots