Bug#653929: Bug #696119 probably has the fix to this bug
On Mon, Dec 17, 2012 at 02:24:42AM +0000, Steven Chamberlain wrote:
> Originally in #653929 it was said that this bug breaks GRUB in some way,
> and could prevent use of RAID-Z as a root filesystem; do you know if
> that is true?
Unfortunately, I don't know the answer to this. I am booting from a
mirrored pool and storing most of my data on a raidz pool. (in part
because I thought raidz booting was not supported) I have never tried
to boot from a raidz pool in freebsd or with grub.
However, I note that booting from raidz is in the NEWS file for
grub2 2.00-7 (sid) but not 1.99-23 (squeeze), so I think that
trouble booting from raidz probably stems from grub, not from this
problem in zpool / libzfs.
To the original poster I'd suggest seeing whether grub2 2.00-7 from sid
enables booting from raidz...