Jonathan Ellis (@spyced) posted a link to an article about using ZFS-FUSE on Linux, ending with this bold claim.

I’m expecting that ZFS-FUSE is going to continue to be the only real option for Linux users to have access to a modern file-system for at least the next 2 years.

There’s only one word for that: bollocks. I happen to work in a group where we get pretty good exposure to everything that’s happening in the Linux-filesystem world, and what Reifschneider says is just not true. His claim that “btrfs is still years away” is just Sun FUD, and Sun hardly needs help in the FUD department. Within a year btrfs will be where ZFS was when it was released. Will it be where ZFS is today? Probably not, but that’s not the correct standard. This isn’t about feature parity; it’s about a “real option” for Linux users, and if btrfs a year from now isn’t good enough then neither was ZFS in 2004 and I’d expect any btrfs critics to admit it. NILFS might also be a “real option” by then as well, though it seems a bit less likely.

No matter what you think of btrfs or NILFS, though, there’s another more important point: ZFS-FUSE isn’t a “real option” either. No FUSE-based local filesystem is or ever will be. Don’t get me wrong – I love FUSE. I use sshfs, which is based on FUSE, every day. FUSE is great for putting a filesystem interface on top of anything else, and even for distributed filesystems where the overhead it incurs is outweighed by network latency. In the specific performance milieu where local filesystems must live that overhead is simply unacceptable, and so are its functional deficiencies (e.g. mapped files). If user-space filesystems were adequate in that role, then everyone – notably including the original ZFS crew – would have switched to writing filesystems that way years ago. They haven’t, and for good reason.

If your workload is such that the ZFS functionality matters more to you than those issues – and the “Ultimate Storage Box” seems to fit that description at a mere 240MB/s by Reifschneider’s own report – that’s wonderful. Knock yourself out. It’s just no excuse to go around dismissing others’ efforts toward something that’s truly industrial strength.