Linux does not support ZFS as well as operating systems like OpenBSD or OpenIndiana, but I do use it on my Ubuntu box for my backup array. It is not the best setup: RAID-Z over USB is not at all guaranteed to keep your data safe, but it was the most economical thing I was able to build myself, and it gets the job done well enough with regular scrubbing to give me piece of mind about at least having one other reliable copy of my data. And I can write files to it quickly, and take snapshots of the state of the filesystem if need be.

I used to use Btrfs on my laptop and it worked just fine, but I did have trouble once when I ran out of disk space. A Btrfs filesystem puts itself into read-only mode when that happens, and that makes it tough to delete files to free-up space. There is a magic incantation that can restore read-write functionality, but I never learned what it was, I just decided to stop using it because Btrfs is pretty clearly not for home PC use. Freezing the filesystem in read-only mode makes sense in a data-center scenario, but not for a home user who might want to try to erase data so one can keep using it normally. I might consider using Btrfs in place of ZFS on a file server, though ZFS does seem to provide more features and seems to be somewhat better tested and hardened.

There is also BCacheFS now as an alternative to Btrfs, but it is still fairly new, and not widely supported by default installations. I don’t know how stable it is or how well it compares to Btrfs, but I thought I would mention it.