I've been experimenting with zfs onlinux in the last few days. ZFS is running fast and stable and all looks great. There is however a small issue with proxmox and the shares mounted from zfs. The preconditions are: By default, zfs will not mount a zfs dataset in a directory if the directory is not empty. By defaults, proxmox will create directories in it's datastore, if it finds it empty. You see the race: Sometimes you dismount a zfs filesystem containting something (images/iso... whatever) and proxmox will create a new empty directory called "images" in the mount point. Some other times, zfs will just have a problem and not mount, leading to the same issue above. ZFS will refuse to mount the dataset until you delete the empty directories. The fix.... is not easy. I know.