That scheme would be far less reliable. For one, if you corrupt a file and don't notice right away, you lose it forever (which sort of defeats the purpose of ba

That scheme would be far less reliable. For one, if you corrupt a file and don't notice right away, you lose it forever (which sort of defeats the purpose of backups, doesn't it?). Also, you wouldn't actually do a full backup every day. You would perform data journaling with periodic snapshots. For example, with daily backups with a change rate of 5%, and monthly snapshots, you need only 2.5x your data size per month ignoring the minimal transaction overhead.