My full-system backups are done with btrfs snapshots synced to an external disk (actually two disks to have two backup locations). It's nice because you can keep the snapshot on your system and don't need the external disk as long as you have enough space, and both filesystems are in almost exactly the same state which makes it easy to mount it for copying a single file or to even boot your system from the external disk.

Same here. Btrfs send/receive made me forget about backup programs. I trigger periodic snapshots with Anacron and never worry about corruption.

I do miss Obnam, nevertheless. The interface was the best.

Might add

zpaq (C++) - http://mattmahoney.net/dc/zpaq.html

to the list.

and especially lzip and lrzip then too.

But zpaq is pure magic...a slow one but with massive compression.

Bup (Python + C) - https://github.com/bup/bup - de duplicated and compressed. Storage format is a fit repository, an interesting choice that lets you restore using just git tools, “cat” and some effort.

So bup has learned to store file metadata (permissions etc), that's neat.

Do you know which of these support a full Windows 10/11 system backup and restore?

I’m trying to avoid the need to reinstall and configure my system (for example, the registry, custom installed and tweaked programs) in case of complete data loss or a migration to new hardware.

My understanding is that full system backups on Windows requires the tool to create VSS snapshots and back up from the snapshot. Any tool that just copies files on the disk won't work.

I use Veeam Agent for this purpose (free, but not open source). It can do full system backups and supports both restoring to the same hardware and new hardware. Restores are done via a bootable WinPE-based image that the tool creates.

One cool thing about it I haven't seen in other backup software is that incremental backups work via a driver that tracks which disk blocks are changed as the system is running. It avoids the need to rescan the disk to detect what has been changed (though it will still do that if the filesystem is modified outside of Windows, eg. if dual booting).

The biggest downside is Veeam's website. It's pretty "enterprisey" and they want you to register to be able to download. I install via the Chocolatey package manager to avoid this. Chocolatey's package source has a direct link to the official installer [0].

There are no ads, nagging, nor upselling in the software itself. I have not seen it making any network connections outside of connecting to my backup target host and the auto-updates server.

I've been looking for open source alternative with a similar feature set, but haven't had too much luck. There's Bacula, but that seems to very much be designed for an enterprise use case.

[0] https://github.com/sbaerlocher/chocolatey.veeam-agent/blob/m...

Windows system backup requires support for correctly handling pretty much every NTFS feature, even (especially) the most obscure ones. While a generic file backup tool works fine for Linux and BSD system backups, it's hopeless for Windows. You need a tool that's specifically designed to do that.

Correct me if I'm wrong, but isn't attic just an older release of Borg?

borg is a fork of attic. Different authors.

attic is python and c

borg is python and c

bupstash is rust and c

Maybe update your list a bit ;)