Having a synced copy elsewhere is not an adequate backup and snapshots are pretty important. I recently had RAM go bad and my most recent backups had corrupt data, but having previous snapshots saved the day.
I would generally argue that rsync is not a backup solution.
Yeah, if you want to use rsync, you’re probably better-off using something like rdiff-backup
, which makes use of rsync to generate backups and store them efficiently.
rsync
: one-way synchronization
unison
: bidirectional synchronization
git
: synchronization of text files with good interactive merging.
rdiff-backup
: rsync
-based backups. I used to use this and moved to restic
, as the backupninja
target for rdiff-backup
has kind of fallen into disrepair.
melfie@lemy.lol 20 hours ago
melfie@lemy.lol 1 hour ago
Don’t understand the downvotes. This is the type of lesson people have learned from losing data and no sense in learning it the hard way yourself.
neidu3@sh.itjust.works 23 hours ago
+1 for rfiff-backup. Been usinit for 20 years or so, and I love it.
koala@programming.dev 6 hours ago
Beware rdiff-backup. It certainly does turn rsync (not a backup program) into a backup program.
However, I used rdiff-backup in the past and it can be a bit problematic. If I remember correctly, every “snapshot” you keep in rdiff-backup uses as many inodes as the thing you are backing up. (Because every “file” in the snapshot is either a file or a hard link to an identical version of that file in another snapshot.) So this can be a problem if you store many snapshots of many files.
But it does make rsync a backup solution; a snapshot or a redundant copy is very useful, but it’s not a backup.
(OTOH, rsync is still wonderful for large transfers.)
tal@olio.cafe 3 hours ago
I think that you may be thinking of
rsnapshot
rather thanrdiff-backup
which has that behavior; both usersync
.But I’m not sure why you’d be concerned about this behavior.
Are you worried about inode exhaustion on the destination filesystem?
koala@programming.dev 2 hours ago
Huh, I think you’re right.
Before discovering ZFS, my previous backup solution was rdiff-backup. I have memories of it being problematic for me, but I may be wrong in my remembering of why it caused problems.