freebsd-snapshot is a set of convenience frontend tools to mount(8) and mdconfig(8) for the management of UFS2 snapshots. It is also the under-lying tool used in the periodic snapshot scheduler periodic-snapshot(8) and the mounting/unmouning command in the amd(8) map /usr/local/etc/amd.map.snap. It provides the making, expiring, visiting, mounting and unmounting of filesystem snapshots. WWW: https://people.freebsd.org/~rse/snapshot/