[PVFS-users] opendx, fgets, big files problem

[Marcelo Matus]

Ok, we found the problem, which is also common to the fwrite problems
reported before in the mainling list that we also observed here.

The buffer=mapped option is not stable in the  Kernel 2.4.21-27.0.4.ELsmp,
using buffer=dynamic solves the OpenDX problems and the buffered
fread/fwrite stdio operations.

Marcelo


Rob Ross wrote:

> Hey,
>
> Can you strace the app and see what system call it's trying to use?
>
> Thanks,
>
> Rob
>
> Marcelo Matus wrote:
>
>> Dear PVFS list:
>>
>> We are trying to read a large binary file from a PVFS directory
>> using OpenDx (which uses fgets to read) and we get the
>> following message
>>
>>  ll_pvfs.c, 610): ll_pvfs_file_read failed on 311457
>>  pvfs_map_userbuf: map_user_kiobuf failed
>>
>> while OpenDx reports that the end-of-file has been reached.
>>
>> The  error occurs after reading around 8MB,  and the same
>> file shows no problem when checked using 'md5sum'. pvfs-ping
>> reports no problem, and all the other applications seem
>> to be running fine.
>>
>> OpenDX also opens the same file with no problem after copying it to
>> a local filesystem such as /tmp.
>>
>> The pvfs version is 1.6.3, kernel version Linux 2.4.21-27.0.4.ELsmp,
>> OpenDX 4.3.2.
>>
>> Any ideas?
>>
>>
>> Marcelo
>
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