Zpool on raw disk and weird GEOM complaint

[Dan Naumov]

On Mon, Jun 29, 2009 at 12:43 PM, Patrick M. Hausen<hausen at punkt.de> wrote:
> Hi, all,
>
> I have a system with 12 S-ATA disks attached that I set up
> as a raidz2:
>
> %zpool status zfs
>  pool: zfs
>  state: ONLINE
>  scrub: scrub in progress for 0h5m, 7.56% done, 1h3m to go
> config:
>
>        NAME        STATE     READ WRITE CKSUM
>        zfs         ONLINE       0     0     0
>          raidz2    ONLINE       0     0     0
>            da0     ONLINE       0     0     0
>            da1     ONLINE       0     0     0
>            da2     ONLINE       0     0     0
>            da3     ONLINE       0     0     0
>            da4     ONLINE       0     0     0
>            da5     ONLINE       0     0     0
>            da6     ONLINE       0     0     0
>            da7     ONLINE       0     0     0
>            da8     ONLINE       0     0     0
>            da9     ONLINE       0     0     0
>            da10    ONLINE       0     0     0
>            da11    ONLINE       0     0     0
>
> errors: No known data errors

I can't address your issue at hand, but I would point out that having
a raidz/raidz2 consisting of more than 9 vdevs is a BAD IDEA (tm). All
SUN documentation recommends using groups from 3 to 9 vdevs in size.
There are known cases where using more vdevs than recommended causes
performance degradation and more importantly, parity computation
problems which can result in crashes and potential data loss. In your
case, I would have the pool built as a group of 2 x 6-disk raidz.

Sincerely,
- Dan Naumov