Right, you are good to do swap files on btrfs since linux 5.0 or so as long as you follow some rules. Disko thankfully covers all those details for you, but I shouldn't have skipped over that in the piece. I'll make an update when I get a chance.
Swap files work, but I wouldn't quite say "you are good to do swap files on btrfs" because the official documentation (the page I linked earlier) says
> filesystem - must be only single device
> This means swapfiles will have an amplified impact, much larger than the size of the swapfile itself.
> Users should be aware of the impact when using swapfiles alongside other data. This is especially discouraged for root filesystem.
If a swap file is the only thing that will work with your setup, then it's fine to use one, but if you're at all able to use a swap partition, then that's a far better choice. (Swap files are fine on ext4 and xfs; it's only COW filesystems like btrfs and zfs where they should be avoided.)
Thanks for this. So weird though - I literally spent the better part of the weekend reading and learning all about the differences between zram and zswap and ultimately deciding to switch out my previous zram config for zswap on my NixOS system! So seeing this pop up on my hackernews feed felt a bit spooky…
I agree with everything else here, but swap files on btrfs should probably be avoided whenever possible [0].
[0]: https://btrfs.readthedocs.io/en/latest/Swapfile.html
Right, you are good to do swap files on btrfs since linux 5.0 or so as long as you follow some rules. Disko thankfully covers all those details for you, but I shouldn't have skipped over that in the piece. I'll make an update when I get a chance.
Swap files work, but I wouldn't quite say "you are good to do swap files on btrfs" because the official documentation (the page I linked earlier) says
> filesystem - must be only single device
> This means swapfiles will have an amplified impact, much larger than the size of the swapfile itself.
> Users should be aware of the impact when using swapfiles alongside other data. This is especially discouraged for root filesystem.
If a swap file is the only thing that will work with your setup, then it's fine to use one, but if you're at all able to use a swap partition, then that's a far better choice. (Swap files are fine on ext4 and xfs; it's only COW filesystems like btrfs and zfs where they should be avoided.)
Thanks for this. So weird though - I literally spent the better part of the weekend reading and learning all about the differences between zram and zswap and ultimately deciding to switch out my previous zram config for zswap on my NixOS system! So seeing this pop up on my hackernews feed felt a bit spooky…