<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.6000.16481" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV><FONT face=Arial size=2>Dear MPI-experts,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I am working on a 16 dual core Beowulf cluster with
MPICH1-2-6 and MPI2-1.0.5p4 and it worked fine for some time.</FONT></DIV>
<DIV><FONT face=Arial size=2>Recently, my /var partition got completely filled
up because a program that I ran wrote a lot of messages in the /var/log
directory.</FONT></DIV>
<DIV><FONT face=Arial size=2>After that, nfs did not work anymore, but after I
made space on /var, it resumed working.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>But in MPICH1.2.6 and MPICH2.1.0.5p4, the master
rank cannot communicate with the slave ranks anymore. Simple test scripts
like cpi, hello++, and fpi run without errors, but they only print
responses from rank 0. Any programs I tried with Send/Recv stall.
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>To see what happens if I run hello++ on a
non-master node, I created a file <BR>"machines" containing only one
line:<BR><BR>node2<BR><BR>and started hello++ like this:<BR><BR>mpirun -np 3
-machinefile ./machines ./hello++<BR><BR>Still, I get the output:<BR><BR>Hello
World! I am 0 of 1</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT><FONT face=Arial size=2>It seems that the master-rank cannot
communicate with the slave, <BR>independently which on which node master and
slaves processes run.<BR>Can anyone think of a possible reason or are there
any further diagnostics?</FONT></FONT></DIV>
<DIV><FONT><FONT face=Arial size=2></FONT></FONT> </DIV>
<DIV><FONT><FONT face=Arial size=2>Thank you,</FONT></FONT></DIV>
<DIV><FONT><FONT face=Arial size=2></FONT></FONT> </DIV>
<DIV><FONT><FONT face=Arial size=2>Christian</FONT></DIV>
<DIV><FONT face=Arial><BR></FONT></DIV><FONT size=2></FONT></FONT>
<DIV><FONT face=Arial size=2></FONT> </DIV></BODY></HTML>