[OpenAFS] zero length core files with OpenAFS 1.6.5

Renata Maria Dart renata@slac.stanford.edu
Mon, 5 May 2014 15:50:18 -0700 (PDT)

Thanks Marc, we'll check out 1.6.6 or 1.6.7.


On Mon, 5 May 2014, Marc Dionne wrote:

>On Mon, May 5, 2014 at 6:31 PM, Renata Maria Dart
><renata@slac.stanford.edu> wrote:
>> Hi, we had a user report that he was only getting 0-length core files
>> from his segfaulting executable when writing the core into AFS from a
>> rhel6 64-bit linux system.  We have confirmed that under OpenAFS 1.6.5
>> this appears to be so.  The executable can write a normal core file on
>> that same linux system if writing to nfs or /tmp.  Is this a known
>> issue that might be fixed in a later version of OpenAFS?
>> A bit more information...we had a rhel6 64-bit linux system running
>> OpenAFS 1.6.1 and a back-level linux kernel 2.6.32-358.23.2 that could
>> successfully write a core file into AFS.  We upgraded the version of
>> OpenAFS to 1.6.5 leaving the kernel at the same older level and now
>> only get 0-length core files when writing to AFS.  The same failure
>> occurs with OpenAFS 1.6.5 and newer linux kernels like
>> 2.6.32-431.11.2.  Core files written to OpenAFS 1.6.2 are also fine.
>> Thanks,
>> Renata
>There was a bug introduced between 1.6.2 and 1.6.3 that could cause a
>problem with core dumps on certain kernels, this was fixed in 1.6.6.
>Another potential issue is that the kernel will check that the owner
>of the file matches the current uid - in case of a mismatch between
>the AFS id and the local uid, the file will get created but no content
>will be written, resulting in a 0-size core file.