ZFS unable to import pool

[Ronald Klop]

On Mon, 21 Apr 2014 21:29:27 +0200, Gena Guchin <ggulchin at icloud.com>  
wrote:

> Hello FreeBSD users,
>
> my appologies for reposting, but I'd really need your help!
>
>
> I have this huge problem with my ZFS server. I have accidentally  
> formatted one of the drives in exported ZFS pool. and now I can’t import  
> the pool back. this is extremely important pool for me. device that is  
> missing is still attached to the system. Any help would be greatly  
> appreciated.
>
>
>
>
> #uname -a
> FreeBSD XXX 10.0-RELEASE FreeBSD 10.0-RELEASE #0 r260789: Thu Jan 16  
> 22:34:59 UTC 2014      
> root at snap.freebsd.org:/usr/obj/usr/src/sys/GENERIC  amd64
>
> #zpool import
>   pool: storage
>     id: 11699153865862401654
>  state: UNAVAIL
> status: One or more devices are missing from the system.
> action: The pool cannot be imported. Attach the missing
>        devices and try again.
>   see: http://illumos.org/msg/ZFS-8000-6X
> config:
>
>        storage                 UNAVAIL  missing device
>          raidz1-0              DEGRADED
>            ada3                ONLINE
>            ada4                ONLINE
>            ada5                ONLINE
>            ada6                ONLINE
>            248348789931078390  UNAVAIL  cannot open
>        cache
>          ada1s2
>        logs
>          ada1s1                ONLINE
>
>        Additional devices are known to be part of this pool, though their
>        exact configuration cannot be determined.
>
>
> # zpool list
> NAME    SIZE  ALLOC   FREE    CAP  DEDUP  HEALTH  ALTROOT
> zroot   920G  17.9G   902G     1%  1.00x  ONLINE  -
>
> # zpool upgrade
> This system supports ZFS pool feature flags.
>
> All pools are formatted using feature flags.
>
> Every feature flags pool has all supported features enabled.
>
> # zfs upgrade
> This system is currently running ZFS filesystem version 5.
>
> All filesystems are formatted with the current version.
>
>
> Thanks a lot!

Does FreeBSD see the disk? Is it in /dev/ada2 (or another number)?
If FreeBSD does not know anything about the disk, ZFS can't either. A  
reboot or some fiddling (partitioning?) with GEOM might make the disk  
reappear.

Ronald.