Copy-on-write snapshots can provide optimal first-tier recoverability at a fraction of the file size, bandwidth, and processing cycles required to clone or mirror a volume. Just don't mistake a copy-on-write snapshot with an actual backup copy.

How Copy-on-Write Snapshots Work

Database administrators take frequent snapshots of the database to provide front-line backup in case of programming or data-entry error. A snapshot preserves the data as it existed at that point-in-time.

The term "snapshot" connotes a copy or picture of the data at a given point in time, but this is misleading. A copy-on-write snapshot doesn't actually copy any data when it is made (except the data structure), and subsequently copies data only before it is overwritten by a change or new data...