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

[Matthew Seaman]

On 23/01/2012 18:06, Chuck Swiger wrote:
> On Jan 23, 2012, at 9:04 AM, Steven Hartland wrote:
>> After some digging we discovered that this was likely due to the
>> fact that the BIOS only enumerates the first 12 disks and this
>> machine has more than that in the root zpool which was a striped
>> raidz2 volume. This in turn means that the bootcode can't complete
>> and hence the machine can't boot.
> 
> As far as I can tell, ZFS best practices guides recommend no more
> than nine drives in a group/pool.  Putting more than that into a
> pool, much less something you are trying to boot from, seems like a
> fine experiment to make but is not something which I would rely
> upon...

Even if you do split up your pool into vdevs using 8 drives, you will
still run into the problem with zfs being unable to assemble the pool
unless it sees all of the drives in it.

Interesting that this only appeared as part of a minor kernel update.
I ran into this myself with 8-STABLE, no indication that there was a fix
possible by juggling kernels.

	Cheers,

	Matthew

-- 
Dr Matthew J Seaman MA, D.Phil.                   7 Priory Courtyard
                                                  Flat 3
PGP: http://www.infracaninophile.co.uk/pgpkey     Ramsgate
JID: matthew at infracaninophile.co.uk               Kent, CT11 9PW

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