Veritas Volume Manager 5.1 SP1 Administrator"s Guide (5900-1506, April 2011)

resynchronization is required on reattaching the snapshot plex. In later releases,
the snapshot model was enhanced to allow snapshot volumes to contain more
than a single plex, reattachment of a subset of a snapshot volume’s plexes, and
persistence of FastResync across system reboots or cluster restarts.
See “FastResync” on page 63.
Release 4.0 of VxVM introduced full-sized instant snapshots and space-optimized
instant snapshots, which offer advantages over traditional third-mirror snapshots
such as immediate availability and easier configuration and administration. You
can also use the third-mirror break-off usage model with full-sized snapshots,
where this is necessary for write-intensive applications.
See “Comparison of snapshot features” on page 62.
For details about the snapshots and how to use them, see the Veritas Storage
Foundation Advanced Features Administrator's Guide.
See the vxassist(1M) manual page.
See the vxsnap(1M) manual page.
Comparison of snapshot features
Table 1-1 compares the features of the various types of snapshots that are
supported in VxVM.
Table 1-1
Comparison of snapshot features for supported snapshot types
Break-off
(vxassist or
vxsnap)
Space-optimized
instant
(vxsnap)
Full-sized
instant
(vxsnap)
Snapshot feature
NoYesYesImmediately available for use on
creation
NoYesNoRequires less storage space than
original volume
YesNoYesCan be reattached to original volume
YesYesYesCan be used to restore contents of
original volume
NoYesYesCan quickly be refreshed without being
reattached
NoNoYesSnapshot hierarchy can be split
Understanding Veritas Volume Manager
Volume snapshots
62