strange zfs pool status/error

[Andriy Gapon]

on 27/07/2010 18:17 Andriy Gapon said the following:
> $ zpool status -v
>   pool: pond
>  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
>         pond                                            ONLINE       0     0     0
>           mirror                                        ONLINE       0     0     0
>             gptid/fcf3558b-493b-11de-a8b9-001cc08221ff  ONLINE       0     0     0
>             gptid/48782c6e-8fbd-11de-b3e1-00241d20d446  ONLINE       0     0     0
> 
> errors: Permanent errors have been detected in the following files:
> 
>         /usr/src/cscope.out


zpool scrub cleared the error.
I am relieved, but still not a nice incident.

> I don't see any errors or suspicious messages in any logs.
> The file in question is perfectly readable (produces stable md5 checksum without
> any errors) and apparently is not too (or at all) corrupt - cscope still works
> fine with it.
> All vdevs are online and there are no vdev errors.
> 
> So what does all this mean and how it can happen?
> In other words, why/how did ZFS decide that that file is corrupted?
> 


-- 
Andriy Gapon