ZFS raidz1 pool unavailable from losing 1 device

[Ludwig Pummer]

Simun Mikecin wrote:
> Ludwin Pummer wrote:
>
>   
>> My system is 7.2-STABLE Jul 27, amd64, 4GB memory, just upgraded from 6.4-STABLE 
>> from last year. I just set up a ZFS raidz volume to replace a graid5 volume I 
>> had been using. I had it successfully set up using partitions across 4 disks, 
>> ad{6,8,10,12}s1e. Then I wanted to expand the raidz volume by merging the space 
>> from the adjacent disk partition. I thought I could just fail out the partition 
>> device in ZFS, edit the bsdlabel, and re-add the larger partition, ZFS would 
>> resilver, repeat until done. That's when I found out that ZFS doesn't let you 
>> fail out a device in a raidz volume. No big deal, I thought, I'll just go to 
>> single user mode and mess with the partition when ZFS isn't looking. When it 
>> comes back up it should notice that one of the device is gone, I can do a 'zfs 
>> replace' and continue my plan.
>>
>> Well, after rebooting to single user mode, combining partitions ad12s1d and 
>> ad12s1e (removed the d partiton), "zfs volinit", then "zpool status" just hung 
>> (Ctrl-C didn't kill it, so I rebooted). I thought this was a bit odd so I 
>> thought perhaps ZFS is confused by the ZFS metadata left on ad12s1e, so I 
>> blanked it out with "dd". That didn't help. I changed the name of the partition 
>> to ad12s1d thinking perhaps that would help. After that, "zfs volinit; zfs mount 
>> -a; zpool status" showed my raidz pool UNAVAIL with the message "insufficient 
>> replicas", ad{6,8,10}s1e ONLINE, and ad12s1e UNAVAIL "cannot open", and a more 
>> detailed message pointing me to http://www.sun.com/msg/ZFS-8000-3C. I tried 
>> doing a "zpool replace storage ad12s1e ad12s1d" but it refused, saying my zpool 
>> ("storage") was unavailable. Ditto for pretty much every zpool command I tried. 
>> "zpool clear" gave me a "permission denied" error.
>>     
>
> Was your pool imported while you were repartitioning in single user mode?
>      
>   
Yes, I guess you could say it was. ZFS wasn't loaded while I was doing 
the repartitioning, though.

--Ludwig