Let's imagine I have pizza pictures stored in my home server, so I encrypt it with whatever Linux uses to encrypt an entire disk. But I also want efficient single-file backups like rsync, not "dd an entire 1TB disk every night". If I simply use a rsync cron job it will copy the files unencrypted, right? How can I have efficient backups with full-disk encryption?
rsync the mounted cleartext to a cleartext mount of another encrypted volume
(lots of overhead)
rsync the ciphertext itself to the other volume
(may not be sufficiently flexible, depending on requirements)