Hi,
We have a 4 node test cluster. One node acts as metadata server and
the others acts as data servers. All of the nodes are clients. On each
data node some programs will be executed and this programs will use
the files stored on pvfs2. However if I ensure that the programs use
the data that is stored on local disk, I will gain a great performance
increase. In order to do this I need to send the data to specific
physical locations [e.g. write file1 to node1, write first N MB of
file2 to node2 etc.]

After some tests I realized that when a node requests a file it first
contacts to metadata server and than it directly contacts to the
server where data is stored - metadata server involves no more- So if
the data is stored on the local disk of this machine than copying a
file will cost approximately the same as a local copy.

I can't figure out why the system accepts "0:4M" and does not accept
"1:4M"! What's the difference between these two strips? If the strip
string is "N:<size>" than why does PVFS2 need to send data to all
nodes 0..N-1 and then node N? Is this a design choice?

Thanks

--
Hamza

On 11/22/05, Thomas Ludwig <[EMAIL PROTECTED]> wrote:
> Hamza,
>
> the varstrip distribution was developed in my group. We also have a
> patch that controls where the data goes. However, it's currently only
> available for version 1.0.1 . Hipolito Vasquez takes care of this and
> will give you further info. We urgently want to have that in place such
> that we can control where the data goes.
>
> Let's keep in contact if you have a good application for this. Thanks.
>
>         Thomas
>
>
> --
> Prof. Dr. habil. Thomas Ludwig           |     Tel: +49-6221-54-4968
> Ruprecht-Karls-Universität Heidelberg    |      or: +49-6221-54-4973
> Institut für Informatik   +--------------+     Fax: +49-6221-54-4404
> Im Neuenheimer Feld 348   |  Office 018  |     [EMAIL PROTECTED]
> 69120 Heidelberg, Germany | http://pvs.informatik.uni-heidelberg.de/
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