I'm running native ZFS on Ubuntu 11.10 with 2x2 TB drives in a mirrored setup. The ZFS file system is mounted directly in Ubuntu and not through NFS or something like that, the permissions are set too 777.
My problem is that when I delete a file it would disappear as you'd expect but when I type zfs list it's still reporting used space as if the file was still there. I've wait a couple of hours and I'm currently running a scrub to see if that fixes it but that shouldn't be necessary, should it?