zfs discuss - Nov 2009 - ZFS non-zero checksum and permanent error with deleted file

Hello,

I am actually using ZFS under FreeBSD, but maybe someone over here can 
help me anyway. I''d like some advice if I still can rely on one of my 
ZFS pools:

[user at host ~]$ sudo zpool clear zpool01
   ...
[user at host ~]$ sudo zpool scrub zpool01
   ...
[user at host ~]$ sudo zpool status -v zpool01
   pool: zpool01
  state: ONLINE
status: One or more devices has experienced an error resulting in data
     corruption.  Applications may be affected.
action: Restore the file in question if possible.  Otherwise restore the
     entire pool from backup.
    see: http://www.sun.com/msg/ZFS-8000-8A
  scrub: none requested
config:

     NAME        STATE     READ WRITE CKSUM
     zpool01     ONLINE       0     0     4
       raidz1    ONLINE       0     0     4
         ad12    ONLINE       0     0     0
         ad14    ONLINE       0     0     0
         ad16    ONLINE       0     0     0
         ad18    ONLINE       0     0     0

errors: Permanent errors have been detected in the following files:

         zpool01:<0x3736a>


How can there be an error in a file that does not seem to exist ?
How can I clear / recover from the error ?

I have read the corresponding documentation and did the obligatory 
research, but so far, the only option I can see is a full destroy/create 
cycle - which seems an overkill, considering the pool size and the fact 
that there seems to be only one (deleted ?) file involved.

[user at host ~]$ df -h /mnt/zpool01/
Filesystem    Size    Used   Avail Capacity  Mounted on
zpool01       1.3T    1.2T    133G    90%    /mnt/zpool01

[user at host ~]$ uname -a
FreeBSD host.domain 7.2-RELEASE FreeBSD 7.2-RELEASE #0: Fri May  1 
07:18:07 UTC 2009 
root at driscoll.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  amd64

Cheers,

ssc

On Wed, 4 Nov 2009, Steven Samuel Cole wrote:
>
> errors: Permanent errors have been detected in the following files:
>
>        zpool01:<0x3736a>
>
>
> How can there be an error in a file that does not seem to exist ?
I don''t know the answer to this.  Maybe it is data retained by a 
snapshot?
> How can I clear / recover from the error ?
It seems likely that this command will clear it:

   zpool clear zpool01

and then you can pretend it did not happen.

Definitely do

   zpool scrub zpool01

to see if there is any other decay.

Bob
--
Bob Friesenhahn
bfriesen at simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/