FreeNAS root on ZFS

[HarryE]

As I am a big fan of ZFS, I tweaked FreeNAS to boot&run completely from ZFS. No UFS at all. On a single 2Gb stick, root filesystem takes 431Mb on ZFS.
Having root on ZFS brings the advantages of customization of the filesystem (rw root) without the worries of "pulling-the-plug" solved by read-only root +MD of nanobsd.
The upgrades/downgrades could be simple zfs receive or clone/rollbacks.


The web interface doesn't see the zpool but sees the snapshots in root zfs.
I suppose I have to go into some sqlite db and manually add something, since the autoimport doesn't work for active zpools.

Any ideas on how to do this?

[survive]

Hi HarryE,

Sounds like a very cool project you have going on there. Be sure to let us know what you find out!

-Will

[HarryE]

Here it is:
I used my regular FreeBSD 8.2 to create 3 partitions on a 2GB stick as described in FreeBSD's Root-on-zfs tutorial, 1 for bootstrap, one for swap, and one for zpool.
Then I created the zpool, named it nanozfs to please the two worlds :-) . Inside I created 3 zfs filesystems named nanozfs/part1, nanozfs/cfg and nanozfs/data.
Next I copied the content of the FreeNAS partitions from another stick into nanozfs/part1, nanozfs/cfg and nanozfs/data filesystems accordingly.
Adjusted loader.conf, fstab, rc.conf and created a necessary fsck_zfs (as a simple exit 0). Removed /conf/default/etc/remount.
At some point there was a "zpool set bootfs=nanozfs/part1 nanozfs" involved.
Since then I found the necessary tables to be modified in order to manually import zfs filesystems into web interface.
In the morning I'll download a newer version of FreeNas, create a nanozfs/part2 filesystem, copy the content + tweaks into it.
Then snaphot nanozfs/cfg, nanozfs/data just in case I want to rollback.
A zpool set bootfs=nanozfs/part2 nanozfs will help to boot the new version.