[Pvfs2-users] NFS trouble

[Sam Lang]

Oh I see.  He's doing NFS over PVFS2.  I guess the NFS server uses aio.
-sam

On Sep 21, 2007, at 9:45 AM, Sam Lang wrote:

>
> Hi Murali,
>
> I'm confused about something.  If Emmanuel is just using cp and mv,  
> why are there multiple segments in the iovec?
>
> Thanks,
> -sam
>
> On Sep 21, 2007, at 9:08 AM, Murali Vilayannur wrote:
>
>> Emmanuel,
>> THat case hasn't been implemented unfortunately..It proved to be a
>> little bit more
>> complicated at the time I wrote it..
>> I did not realize that there is a need or use case for nr_segs > 1.
>> Hmm. Until we get the fully correct solution,
>> one temporary kludge is to open pvfs2-config.h and comment out the  
>> line
>> #define HAVE_COMBINED_AIO_AND_VECTOR 1
>> and then rebuild the kernel module (using make kmod)
>> Hope this works,
>> thanks,
>> Murali
>>
>>
>>
>> On 9/20/07, Emmanuel Florac <eflorac at intellique.com> wrote:
>>>
>>> Hello,
>>> I've built a small PVFS2 cluster and it works fine -- mostly...
>>>
>>> Here is the basic cluster setup : 2 dual core Xeon machines, 2GB
>>> RAM, 2 TB disks as server nodes. Running Debian Etch with a custom
>>> 2.6.20.7 SMP kernel built from kernel.org vanilla source.
>>> I compiled PVFS 2.6.3, with the 2.6.21 patch applied (it wouldn't
>>> compile as is).
>>>
>>> PVFS2 works just fine, local performance is OK.
>>> I'd need to share the PVFS2 filesystem thru NFS to some clients.
>>> Reading just works, however writing constantly fails with this  
>>> error :
>>>
>>> Sep 19 18:36:53 triangle
>>> kernel: /usr/sarge64/usr/src/pvfs-2.6.3/src/kernel/linux-2.6/file.c
>>> line 1923: pvfs2_file_aio_write_iovec: not implemented yet (aio  
>>> with 7
>>> segments)
>>>
>>> Then the file created is either of zero size, or filled with 0x00.
>>>
>>> I've tried many configurations : sharing from a PVFS2
>>> both server and client node, from a PVFS2 client-only node, with
>>> uniprocessor and smp kernel, forced NFS version 2, no luck.
>>>
>>> Writing thru CIFS (Samba), FTP, scp works perfectly.
>>>
>>> I tentatively edited the file.c source code by commenting out the  
>>> test
>>> that spits the error out. With this modified kernel module, writing
>>> thru NFS works _most_of_the_time_. It fails apparently randomly from
>>> time to time while writing big files ( 500MB to 1GB).
>>>
>>> Any help would be greatly welcomed....
>>>
>>> --
>>> ----------------------------------------
>>> Emmanuel Florac     |   Intellique
>>> ----------------------------------------
>>>
>>> _______________________________________________
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>>>
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>