LAM MPI hangs the hamachi driver

[Anthony Caola]

Hello all -

I have a parallel MPI code that appears to be hanging the hamachi driver and 
G-NIC II card.  The symptoms right now are like this:

1 - When the code becomes communication intensive, one of the nodes will drop 
off the network.  ifdown and ifup'ing eth0 sometimes clears the trouble.
2 - If I do anything to slow my code - compile at the -g level or turn on 
debugging in the hamachi driver (options debug=6 hamachi) - everything 
finishes successfully, but slower.

I'm going to start tearing apart this problem and try to get to the bottom of 
this, but was hoping someone might have seen some kind of 'overflow' type of 
problem in the past.  Maybe all I need to do is increase one of the tunable 
parameters. . .

Our setup is as follows:

16 dual processor pentium xeon III's (dell 610 precision workstations) with 
G-NIC II's running Linux 2.2.12.  We use a PowerRail 2200 switch for the 
interconnect.

Thanks!

Anthony



Anthony Caola                Massachusetts Institute of Technology
Phone:  (617) 253-6547       Department of Chemical Engineering
Fax:    (617) 258-8224       25 Ames St., Building 66-250
Email:  caola@mit.edu        Cambridge, MA  02139


 | To unsubscribe, send mail to Majordomo@cesdis.gsfc.nasa.gov, and within the
 |  body of the mail, include only the text:
 |   unsubscribe this-list-name youraddress@wherever.org
 | You will be unsubscribed as speedily as possible.