[Pvfs2-users] Number of data transfer messages

[Michael Moore]

Hi Wantao,

In the situation you describe a single request will be sent to each server
for your application's I/O request. When accessing a file the client needs
to know what datafile handles are associated with the file, done via a
getattr request, after that the client can perform I/O without contacting
the metadata server. However, if the client updates attributes (atime,
mtime, etc) as typically happens when using the kernel client interface,
there will be a setattr request to the metadata server.

Hope that helps,
Michael

On Wed, Jun 29, 2011 at 3:20 AM, Wantao <liu_wantao at qq.com> wrote:

> Hi, all
>
> I have a PVFS2 installation with three IO servers and 64KB strip size. my
> application requests 256KB in one IO operation(read or write). So, it needs
> two continuous strips from server1 and one strip from server 2 and 3. In
> this case, how many data transfer messages are needed for server1? Can it
> send or receive two strips in one message?  Another question is that when
> accessing a big file, does PVFS2 need to interact with meta server for each
> IO operation?
>
> Thanks for all advice.
>
> Wantao
>
>
>
> _______________________________________________
> Pvfs2-users mailing list
> Pvfs2-users at beowulf-underground.org
> http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.beowulf-underground.org/pipermail/pvfs2-users/attachments/20110629/af436ae1/attachment.htm