ZFS failed after hard power off

[Šimun Mikecin]

On 1. tra. 2011., at 03:36, Jeremy Chadwick wrote:

> On Fri, Apr 01, 2011 at 12:36:47AM +0000, Piotr Paczynski wrote:
>>> v28 was committed to -current on Feb 27th, so your snapshot is too
>>> old. You should be able to fix the pool with OpenIndiana liveDVD or
>>> liveUSB
>>> http://openindiana.org/download/
>> 
>> OK, after fiddling for like 4 hours I managed to run OpenIndiana
>> LiveDVD (wouldnt boot up which eventually turned out to by my KVM
>> fault) and then get it to see my 3ware 9650 arrays (needed to install
>> drivers from 3ware). The problem is my corrupted pool is not visible
>> by zpool command. Now, I have two pools on the server: zroot and
>> backup. The backup is visible (and not faulted) but zroot is not
>> visible under Solaris - this is the one I have problems with, and also
>> use as boot disk in FreeBSD:
>> 
>> root at openindiana:~# zpool import
>> pool: backup
>>   id: 8416389847782759507
>> state: ONLINE
>> status: The pool is formatted using an older on-disk version.
>> action: The pool can be imported using its name or numeric identifier, though
>> 	some features will not be available without an explicit 'zpool upgrade'.
>> config:
>> 
>> 	backup        ONLINE
>> 	  mirror-0    ONLINE
>> 	    c4t1d0p0  ONLINE
>> 	    c4t2d0s2  ONLINE
>> root at openindiana:~# zpool import zroot
>> cannot import 'zroot': no such pool available
>> root at openindiana:~# zpool import -fFn zroot
>> cannot import 'zroot': no such pool available
> 
> I believe the command here is wrong, and that you should be using "zpool
> import 8416389847782759507" or "zpool import 8416389847782759507 zroot".
> I've seen many cases where using the pool name doesn't work.

He has two pools: backup and zroot. Only backup is visible.
So he shouldn't do as you suggested, because it will rename his backup pool to zroot, which will bring the confusion, because it is not the original zroot pool.
To be able to import his original zroot pool, it needs to be visible to "zpool import" as a first step.