zfs: allocating allocated segment

[Michael Gusek]

Peter Schuller schrieb:
>> I'm running a File server with zfs, 64 Bit, 4 GB Ram and RELENG_7. Two days 
>> ago i uploaded a file via ftp to the server and the server is crashing. After 
>> reboot FreeBSD can't import the zfs-pool. There is a kernel-message:
>>
>> panic: Solaris(panic): zfs: allocating allocated 
>> segment(offset=123456... size=74)
>>
>> cpuid = 0
>> Uptime: 14m22s
>> panic: bufwrite: buffer is not busy???
>>
>> Now i try to import the zfs-pool with a recent 8.0-current but with the same 
>> result. It's very important to me to access the pool, so did you have some 
>> idea's ?
>>     
>
> The ZFS panic is from space_map.c in space_map_add(), happening via
> zfs_panic_recover(). It in turn is affected by zfs_recover:
>
> /*                                                                                                                                                                                                                                             * zfs_recover can be set to nonzero to attempt to recover from                                                                                                                                                                                * otherwise-fatal errors, typically caused by on-disk corruption.  When                                                                                                                                                                       * set, calls to zfs_panic_recover() will turn into warning messages.                                                                                                                                                                          */
>
> Setting the vfs.zfs.recover loader variable to 1 might possibly
> help. However I have never tried using that option and I'm not
> familiar with the code, so I have no idea how safe it is. In
> particular since you then seem to be getting a secondary panic (the
> "buffer is not busy" which is from ffs_vfsops.
>
> On another note:
>
> http://www.google.com/search?client=opera&rls=en&q=zfs:+allocating+allocated+segment&sourceid=opera&ie=utf-8&oe=utf-8
>
> indicates you're not the only person who has seen similar
> errors. Unfortunately I cannot offer any insight other than to suggest
> digging through the google results.
>
> Was the original crash, prior to the mount problem, purely a software
> crash or was there, for example, a power outtage? I'm wondering
> whether there is any particular reason to believe there was some
> hardware/firmware fault causing corruption.
>
>   
Thank you for your response Petter,

on Monday i will give vfs.zfs.recover a try. The original crash was 
beeing a ftp upload. There was'nt a power outtage or another kernel 
message, so i don't think it is an hardware issue.

Regards,

Michael