Veritas Storage Foundation 5.1 SP1 Advanced Features Administrator"s Guide (5900-1503, April 2011)

In this example, Persistent FastResync is enabled on volume v1, and Non-Persistent
FastResync on volume v2. Lines beginning with v, dp and ss indicate a volume,
detached plex and snapshot plex respectively. The %DIRTY field indicates the
percentage of a snapshot plex or detached plex that is dirty with respect to the
original volume. Notice that no snap objects are associated with volume v2 or with
its snapshot volume SNAP-v2.
If a volume is specified, the snapprint command displays an error message if no
FastResync maps are enabled for that volume.
Adding a version 0 DCO and DCO volume
The version 0 DCO log volume was introduced in VxVM 3.2. The version 0 layout
supports traditional (third-mirror break-off) snapshots, but not full-sized or
space-optimized instant snapshots.
To put Persistent FastResync into effect for a volume, a Data Change Object (DCO)
and DCO volume must first be associated with that volume. When you have added
a DCO object and DCO volume to a volume, you can then enable Persistent
FastResync on the volume
Note: You need a FastResync license key to use the FastResync feature. Even if
you do not have a license, you can configure a DCO object and DCO volume so that
snap objects are associated with the original and snapshot volumes.
253Administering volume snapshots
Adding a version 0 DCO and DCO volume