[Bioclusters] Login & home directory strategies for PVM?

[Michael Gutteridge]

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 master.

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

Michael