ZFS: i/o error - all block copies unavailable on large disk number machines

[Freddie Cash]

On Mon, Jan 23, 2012 at 11:21 AM, Steven Hartland
<killing at multiplay.co.uk> wrote:
> Not something I've seem made clear, but quite possibly. Even with
> 9 disks you could easily get this if the BIOS doesn't see all of
> said disks, be that initially or due to disks added to the machine.
>
> For reference the original install was done on a zpool with 6 disks
> in a raidz2 config but then 6 additional disks where added to expand
> capacity.
>
> It was only when the new kernel was installed that data required
> to boot was then written to disks in the seconds raidz2 which is
> inaccessible to the boot code even though in perfect working order
> on a booted system.
>
> So something to document, watch out for and potentially safe
> guard against?
>
> It maybe something specific to machines with legacy BIOS hence not
> an issue with Sun kit?

>From what I've gathered on the zfs-discuss mailing list, Solaris only
supports rpool's (bootable pool) to use mirror vdevs, and only a
single vdev in the rpool.

FreeBSD is (AFAIK) the only ZFS implementation that supports booting
from a raidz vdev, and from a pool with multiple raidz vdevs.

IME, separating the bootable disks from the storage disks will always
save you time, effort, and grief in the long run.  :)  Whether that
means using a separate UFS / filesystem, or a mirrored set of disks
for /, or a separate ZFS pool with a single mirror vdev is up to the
admin.  But boot/OS should be separate from bulk storage.  :)

-- 
Freddie Cash
fjwcash at gmail.com