boot code compatibility with ZFS

[Aristedes Maniatis]

FreeBSD has recently been able to boot directly from ZFS as deailed here:

   http://wiki.freebsd.org/RootOnZFS

Naturally having functional boot code has been key to this, but it is very confusing as to why sometimes I can get FreeBSD to boot nicely and sometimes not. From comments in threads and my experience, I've got the following rough timeline:

FreeBSD 7.1: ZFS version 6, no ZFS boot capability
FreeBSD 7.2: ZFS version 6, zfsboot only, boot from single vdev pool only
FreeBSD 7.3: ZFS version 13, zfsboot broken, no ZFS boot capability

FreeBSD 8.0: ZFS version 13, gptzfsboot and zfsboot, boot from mirrored pool or single vdev, RAIDZ not supported, degraded pool not supported


My questions:

1. Is the above list correct?

2. What is the situation for the two stable branches?

3. In an effort to get a machine booting properly I tried installing the boot code from 8-STABLE with a 8.0 kernel. That didn't work. What is the situation with backward and forward compatibility of the boot code? Will there come a time when an OS update will require an update of the boot code?


If someone were able to put these answers on the wiki page as well, I believe this would help others.


Thanks
Ari Maniatis

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Aristedes Maniatis
ish
http://www.ish.com.au
Level 1, 30 Wilson Street Newtown 2042 Australia
phone +61 2 9550 5001   fax +61 2 9550 4001
GPG fingerprint CBFB 84B4 738D 4E87 5E5C  5EFA EF6A 7D2E 3E49 102A

-- 
-------------------------->
Aristedes Maniatis
ish
http://www.ish.com.au
Level 1, 30 Wilson Street Newtown 2042 Australia
phone +61 2 9550 5001   fax +61 2 9550 4001
GPG fingerprint CBFB 84B4 738D 4E87 5E5C  5EFA EF6A 7D2E 3E49 102A