unable to offline a failing drive in a zfs RAIDZ

[Aryeh M. Friedman]

Dan Nelson wrote:
> In the last episode (Mar 01), Aryeh Friedman said:
>   
>> I have a raidz setup as per the handbook but when I attempt to "offline" a
>> failing drive it will not let me:
>>
>> kate# zpool status -c
>> invalid option 'c'
>> usage:
>>         status [-vx] [pool] ...
>> kate# zpool status -v
>>   pool: storage
>>  state: ONLINE
>>  scrub: resilver completed with 0 errors on Mon Mar  1 17:36:48 2010
>> config:
>>
>>         NAME        STATE     READ WRITE CKSUM
>>         storage     ONLINE       0     0     0
>>           raidz1    ONLINE       0     0     0
>>             ad7     ONLINE       0     0     0
>>             ad8     ONLINE       0     0     0
>>             ad9     ONLINE       0     0     0
>>             ad10    ONLINE       0     0     0
>>             ad12    ONLINE       0     0     0
>>
>> errors: No known data errors
>> kate# zpool offline storage ad12
>> cannot offline ad12: no valid replicas
>>     
>
> What version of FreeBSD are you running?  This looks like a known bug.  It
> originally worked for mirrors but not RAIDZ vdevs - "zpool offline is a bit
> too conservative":
>   

FreeBSD kate.istudentunion.com 7.2-RELEASE-p1 FreeBSD 7.2-RELEASE-p1 #0: 
Tue Jun  9 21:30:43 UTC 2009     
root at i386-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC  i386

> http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=2171359 , and
> works for me on a 7-stable kernel:
>
> (root at studio) /root># uname -a
> FreeBSD studio.evoy.net 7.3-PRERELEASE FreeBSD 7.3-PRERELEASE #53: Tue Feb 2 17:19:46 CST 2010 zsh at studio.evoy.net:/usr/src-7/sys/amd64/compile/STUDIO  amd64
> (root at studio) /root># mdconfig -a -t swap -s 1g ;  mdconfig -a -t swap -s 1g ; mdconfig -a -t swap -s 1g
> md1
> md2
> md3
> (root at studio) /root># zpool create dummy raidz md1 md2 md3
> (root at studio) /root># zpool offline dummy md2
> (root at studio) /root># zpool status dummy    
>   pool: dummy
>  state: DEGRADED
> status: One or more devices has been taken offline by the administrator.
>         Sufficient replicas exist for the pool to continue functioning in a
>         degraded state.
> action: Online the device using 'zpool online' or replace the device with
>         'zpool replace'.
>  scrub: none requested
> config:
>
>         NAME        STATE     READ WRITE CKSUM
>         dummy       DEGRADED     0     0     0
>           raidz1    DEGRADED     0     0     0
>             md1     ONLINE       0     0     0
>             md2     OFFLINE      0     0     0
>             md3     ONLINE       0     0     0
>
>
>