linux-timemachine VS btrbk

> I am concerned about the longevity of my archives

If you're concerned about archival longevity, and I for one certainly are, then maybe consider not to compress at all. Both compression and encryption add to obscurity and loss of redundancy in the backup. Using a widely understood file system and a very obvious arrangement of the data (for me that means: directories with dates, below a tree of files that mimics their original locations) will be a huge plus should the data have to be recovered at some point in the future.

Personally I am using a slightly adapted version of https://github.com/cytopia/linux-timemachine for this task. You do get de-duplication for the file transfer, but each file is written as it was on the target. You'll get a timestamped directory for each time a backup was run. Like MacOS' timemachine, the script uses hard links to de-duplicate identical files across different timestamped directories so the overall space requirement for that incremental backup you did an hour or a day later can be very small.

I can certify that this setup, while it does not occupy the least conceivable amount of storage area, is very amenable to be searched and trivial to use for recovery. much better in this regard than any kind of compressed archive format which are always a pain in terms of searchability and so on.

And for file version history and to protect against accidental deletion i use linux-timemachine which backs up over SSH to the same server and keeps versioned incremental backups. This backup also includes my entire /home folder so all apps, appdata and config is contained here.

Linux-TimeMachine: https://github.com/cytopia/linux-timemachine

If you only want to backup specific folders i like the tool linux-timemachine which uses rsync and hardlinks to create incremental backups based on a input and output folder.

You know, another option might be to just rely on something external to your machine if you're worried enough. When I'm dealing with personal machines (usually servers) that are important to me, I usually use Backblaze B2. You could maybe even try using open source variants of Time Machine designed for Linux machines or Borg Backup...though, to be fair, I've never really tried using them for backing up my entire system ( "/" ) partition (https://github.com/cytopia/linux-timemachine).

linux-timemachine

That's still easier using snapshots and something like btrbk. Snapshot the directory at start, prune if there are too many snapshots (or snapshots get too old).

I'm on Arch, but you might still find it useful: Btrfs snapshots Arch Wiki - Incremental backup to external drive GitHub - btrbk

the smoothest backup tool i have seen for Linux is btrbk works real nice and is customizable for almost all use-cases BTRFS rocks :)

I recommend redundancy and regular verification is you want to insure your data against corruption. If you do that, you can forget about things like ECC. My setup is a NUC server running Ubuntu with a USB3-connected storage drive running BTRFS. I use btrbk to auto-snapshot and auto-replicate via incremental sends to my BTRFS backup drive, and RotKraken to track integrity of the data with a monthly verification run so that I notice corruption in time to correct it.

In pondering my backup strategy, I was wondering if I could use BTRFS snapshots and a backup tool like btrbk, which is a nice integrated snapshot/backup solution I've used happily on desktop Linux. BTRFS needs subvolumes for snapshots, so I couldn't backup the host itself (which wasn't installed with a / subvolume like other distributions I've used), but it could snapshot the VMs and containers, which have their own individual subvolumes. Then btrbk can send that snapshot in an incremental fashion to external storage.

I then installed btrbk and tried to follow the instructions to create snapshots of root and home on the SSD and then send/receive those to the HDD. I mainly used https://github.com/digint/btrbk and https://mutschler.dev/linux/fedora-btrfs-35/, but I don't use luks.

For anyone using btrfs on their system, I heartily recommend btrbk, which has served me very well for making incremental backups with a customizable retention period: https://github.com/digint/btrbk

btrbk is the best solution I know.

I use BTRBK to make and copy the BTRFS snapshots to my HDD. I schedule it to run every 3 hours using a Sytemd unit file through my own script to avoid running the backup at inconvenient moments: