Going back 20 years with Oracle DB it was common to use "triple mirror" on storage to make a block level copy of the database. Lock the DB for changes, flush th

Going back 20 years with Oracle DB it was common to use "triple mirror" on storage to make a block level copy of the database. Lock the DB for changes, flush the logs, break the mirror. You now have a point in time copy of the database that could be mounted by a second system to create a tape backup, or as a recovery point to restore. It was the way to do it, and very easy to manage.