Cannot import raidz pool after zero fill one hdd.

[Bartosz Stec]

W dniu 2010-05-26 13:57, Mark Stapper pisze:
> On 23/05/2010 16:57, Bartosz Stec wrote:
>    
>> After a while I've checked zpool status and ad0 was indeed offline,
>> but with about 200  errors? Shouldn't  ZFS stop using this drive at all?
>>      
> ZFS just noticed it should have written/read from the drive, but
> couldn't/wouldn't because it's marked offline.
>    
>> After reboot loader shows some LBA errors and that it cannot find
>> zpool. I've booted this machine using about month old freebsd-current
>> snapshot and got into fixit environment.
>> Here's output of zpool import:
>> http://img715.imageshack.us/img715/7860/19843139.jpg
>>      
> Seems like there's no label "disk1". Logically, because you zerofilled
> the disk...
> Did you re-label the partition?
>    
>> Zroot is in UNAVAIL state because of ad2p3 OFFLINE (which was never
>> offline), gpt/disk1 UNAVAIL, which is the same partition as ad1p3
>> which is showed as ONLINE.
>>      
> Could it be ad2p3 got the label "disk0"?
>
>
>    
Arrrrgh, I tried re-labelling and a lot of other things, without 
success. Now I am almost certain that It was my mistake - I didn't check 
if /dev/gpt/disk0 was placed on ad0 (yes, definitely stupid assumption), 
and probably it wasn't. It was probably ad2p3 which was labelled disk0. 
So It seems that I putted one partition offline, and zeroed other, while 
it was online, which ended with broken raidz1. ZFS seems to read 
metadata from partitions when you are trying to import zpools instead of 
rely on glabel, so changing labels ends only with zfs stop using them.
Thankfully I have found hdd I used to temporarily store all data from 
this machine when I migrating my installation from mixed UFS/ZFS to 
ZFS-only and all data was still there. Dated march 31 but definitely 
better than nothing ;) Lesson taken, problem "solved".

Still, I'm interested if it's possible to mark offline vdev online again 
before importing?
Cheers.

-- 
Bartosz Stec