[Pvfs2-users] PVFS2 slow situation

[Luiz Mendes]

Hi all,

I have installed PVFS2 in 2 PCS with Gigabit Network between them. I am
doing write and read tests between NFS and PVFS2.

I developed a program in MPI that uses 2 processes to write to separate
discs in PVFS2, and after this, the program measure time taken to write file
until time to read this one recently created.

And i developed another program in MPI where 2 processes create a vector
itself, and in this case, process 1 pass it vector to process 0, and process
0 gather itself vector and another from process 1. After gather this one, it
write to a file. And later i read with only one process the whole file that
have created.


I think that the program with PVFS2 should be faster than this second
program that uses NFS, due to the fact of mpi application that uses PVFS2,
each process write to a file, without communication.

But the result is the oposite of that.

Is this behavior correct? In what situations PVFS2 would be better than NFS?

Thanks
Luiz Mendes
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.beowulf-underground.org/pipermail/pvfs2-users/attachments/20070203/158eaafa/attachment.htm