On 2 Sep 2023 00:04 +0200, from [email protected] (Michel Verdier): > rsnapshot use hard links on the backup filesystem.
More accurately, rsnapshot (which is basically a frontend to rsync) tells rsync to do that; IIRC by passing --link-dest pointing at the previous backup target directory. And this is not an argument against rsnapshot/rsync; I use the combination myself, plus a home-grown script to prune old backups based on the amount of free space remaining on the backup disks rather than a fixed backup count. The one big downside of rsnapshot + rsync at least for me is that it has no real concept of whether a backup run completed or was aborted; the latter, for example, due to a system shutdown or out-of-memory condition while it's running. That really shouldn't happen often or even at all, but I've had it happen a few times over many years, and it's a bit of a pain when it does happen because you pretty much have to go in and delete the most recent backup and then renumber all the previous ones to get back into a sane state on the backup target. Yes, that can be added with another piece of a wrapper script, and I have on occasion contemplated doing just that; but it happens sufficiently rarely, and is noisy enough when it does happen, that it isn't really worth the effort in my particular situation. The biggest issue for me is ensuring that I am not dependent on _anything_ on the backed-up system itself to start restoring that system from a backup. In other words, enabling bare-metal restoration. I figure that I can always download a Debian live ISO, put that on a USB stick, set up an environment to access the (encrypted) backup drive, set up partitions on new disks, and start copying; if I were using backup software that uses some kind of custom format, that would include keeping a copy of an installation package of that and whatever else it needs for installing and running within a particular distribution version, and making sure to specifically test that, ideally without Internet access, so that I can get to the point of starting to copy things back. (I figure that the boot loader is the easy part to all this.) -- Michael Kjörling 🔗 https://michael.kjorling.se “Remember when, on the Internet, nobody cared that you were a dog?”
