Shadow filesystems can be snapshotted, however the state of what is included in
the snapshot is arbitrary. Files that have not yet been migrated will not be
present, and implementation details (such as SUNWshadow extended attributes) may be
visible in the snapshot. This snapshot can be used to restore individual files that
have been migrated or modified since the original migration began. Because of this,
it is recommended that any snapshots be kept on the source until the migration is
completed, so that unmigrated files can still be retrieved from the source if
necessary. Depending on the retention policy, it may be necessary to extend
retention on the source in order to meet service requirements.
While snapshots can be taken, these snapshots cannot be rolled back to, nor can
they be the source of a clone. This reflects the inconsistent state of the on-disk
data during the migration.