[Bioclusters] Login & home directory strategies for PVM?

Ruotti, Victor vruotti at mcw.edu
Fri Feb 4 11:17:40 EST 2005

We had a few related problems when using PVM with NFS. NFS just didn't
behave properly in our case. When it comes to large clusters we tent to stay
away from using NFS at all.


-----Original Message-----
From: Michael Gutteridge [mailto:mgutteri at fhcrc.org] 
Sent: Friday, February 04, 2005 12:46 AM
To: bioclusters at bioinformatics.org
Subject: [Bioclusters] Login & home directory strategies for PVM?

Hi all

I'm getting ready to roll out another cluster that will be running a PVM
based application.  I've run into what I think is a bit of an issue with
regards to the PVM daemon startup, NFS mounted home directories, and
scalability with large node-sets.

We've got 62 nodes that will each host 6-10 pvmd's.  The problem I'm
foreseeing is that when the PVM is started, that'll initiate a login to each
of those 62 nodes, a login process which will mount the user's home
directory from an NFS server.  So that could mean quite a few mounts (62 *
10+ unique users), which I suspect would have a detrimental effect on the
NFS server.  Either way, I feel this is an approach that won't scale.

For this application, each of the slave pvmd's doesn't need access to
anything, really, as all of the necessary data is passed to the slave via a
PVM message.  Doesn't even really need to run as any particular user, just
needs to be able to spawn a slave PVM process that can connect to the

I don't believe this problem to be specific to PVM, but could be an issue
with any parallel machine using large node sets.  I'm curious as to
strategies anyone else has used to mitigate the problem I've described,
especially for circumstances such as this, where the slave nodes are merely
compute donors.

Thanks much


Bioclusters maillist  -  Bioclusters at bioinformatics.org

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