This is my #1 question. Can we use it for the root FS? If so, that's amazing, as there are already btrfs-based tools for snapshotting every time you run apt, etc.

There are a couple of open bugs[1][2] related to grub and ZFS that make it a little tricky to get ZFS on your root volume, but it is doable: https://github.com/zfsonlinux/pkg-zfs/wiki/HOWTO-install-Ubu....

I expect those issues to be resolved before 16.04 is released. Even with those fixes, the interactive installer doesn't support ZFS yet so you will still need to drop to a shell to actually setup your zpool and your partitions.

[1]: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1527727...

[2]: https://bugs.launchpad.net/ubuntu/+source/zfs-initramfs/+bug...

You could also use NixOS, which is even better at this. :)

And also has native support for ZFS, btw.

Or indeed PC-BSD. (-:

PC-BSD's installer understands ZFS. It creates an all-ZFS system, including the root volume. The boot manager uses ZFS for "boot environments".

* http://download.pcbsd.org/iso/10.2-RELEASE/amd64/docs/html/i...

* https://www.ixsystems.com/whats-new/2013/10/31/the-revamped-...

* https://blog.pcbsd.org/2013/06/pc-bsd-status-update/