[MPICH] striping_unit Hint Question

[Weikuan Yu]

Robert Latham wrote:
> On Thu, Feb 08, 2007 at 10:43:48PM -0600, Erich Peterson wrote:
>> Hi, I'm very new to MPICH2 and had a question concerning the hint
>> striping_unit. I'm wondering first does MPICH2 implement this hint
>> and when will it follow the hint and when will it not. 
> 
> MPICH2 does implement striping_unit, but it has meaning only for
> parallel file systems.  PVFS, for example, honors the hint, while NFS
> does not.

I assume PVFS/PVFS2 stripe to all IO servers by default, is that right?

Any pointer to a guide on PVFS2 striping usage? I only found one on 
PVFS-user-guide.
http://www.parl.clemson.edu/pvfs/user-guide.html

Thanks,
Weikuan

> 
>> Lastly, if I create a file with this hint, if I then open and append
>> or otherwise write to that file, will the new data inserted also be
>> striped using the same number bytes as was given when the file was
>> created?
> 
> I think for most parallel file systems the striping parameters are set
> when the file is created.  
> 
> ==rob
>