I’d been using ZFS with Void linux on both my laptop and desktop for a couple of months. And ZFS is cool! But I’m thinking not great for my use case, especially for my laptop with it’s more constrained resources. Memory usage was a real problem, even after imposing low ARC limits. And the kernel module compile time was long enough to be a bit annoying, especially for a few kernels (I like to keep the last few around, to be safe) as it happens fairly often on a rolling release.

I switched the laptop to LUKS/btrfs a couple of days ago. And I’m thinking that was the correct choice for that. And now I’m considering doing the same for my desktop. As they seem comparable but btrfs is in-kernel and seemingly more system resource friendly. But before doing so I figured I’d ask the community about it. Maybe some important factors or features for either setup that I might not be considering.

Here’s the stuff I care about. All of which both offer, but I’m not an expert at either and I don’t know how equal they are.

  • Disk encryption. For ZFS everything (except the EFI partition) is encrypted. I use ZFSBootMenu in this scenario. For the btrfs setup I have the kernel/initramfs on an ext2 partition. I do not store any decryption keys in the initramfs. I know grub can decrypt LUKS with limitations, but I prefer this setup. And it feels secure enough to me. Any pitfalls I’m missing?
  • Pools/subvolumes
  • Snapshots. ZFSBootmenu has an option to load a snapshot. For btrfs it looks like I’d need to create a subvolume from a snapshot, which in a recovery situation might mean doing this from recovery media. That’s ok, given this is an unlikely thing to encounter. But if anyone knows of an easier way, I’d love to hear it.
  • CoW
  • RAID 1
  • Compression is nice, especially for the laptop

Edit: typo in title.

  • flatbield@beehaw.orgEnglish
    1·
    1 day ago

    Ext4 on LVM can do both volume mirroring and snapshots. The is no COW support with ext4 though.

    By the way I use BTRFS with LUKS on my workstation and have for 4 or 5 years. Primarily I like it for the snapshoting. I though I would like COW but frankly very mixed on that especially since there are cases you should not use COW and if you disable COW you loose snapshotting on that file. I have not used the raid capability. One thing I do not like about BTRFS is that I know of no way to track a bad block at the sector level to what file it is in if any. With Ext4 you can.

    Another useful backup tool is restic.