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<DIV dir=ltr align=left><SPAN class=453103005-15032010><FONT color=#0000ff
size=2 face=Arial>Can you send us a small test program that
fails?</FONT></SPAN></DIV><BR>
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<FONT size=2 face=Tahoma><B>From:</B> mpich-discuss-bounces@mcs.anl.gov
[mailto:mpich-discuss-bounces@mcs.anl.gov] <B>On Behalf Of
</B>hossam<BR><B>Sent:</B> Sunday, March 14, 2010 1:57 PM<BR><B>To:</B>
mpich-discuss@mcs.anl.gov<BR><B>Subject:</B> [mpich-discuss] MPI I/O SLOW-
possible conflicting withcommunication....code stuck for ever during
IO<BR></FONT><BR></DIV>
<DIV></DIV>Hi,<BR><BR>I think i have a well defined problem i wonder if
someone can give an advice.<BR><BR>I am running an MPI code (MPICH2) on a
linux cluster. <BR><BR>When i run the code with no IO inside the main runtime
loop. It works perfectly fine on any number of processors and nodes. When i
start dumping data during the loop<BR>the code get stuck for ever after the
second or third file. <BR><BR>Everything works perfectly fine on a single
processor though.<BR><BR>Now, to make things clearer: When i use ROMIO (MPI
IO) it got stuck during opining the file (MPI_FILE_OPEN). <BR><BR>However, i
tried regular open(....) at the root processor and then reducing the data to
the root processor and write there. The code got stuck at the MPI_REDUCE
call.<BR><BR>If i eliminated all the processors communication and just do dump
IO (both ways), it runs fine but it slows down significantly when dumping the
data.<BR><BR>I tried on three different clusters(all linux) and i got the same
problem.<BR><BR>I don't want say what i think is the problem, i don't really
know, but if the experts here can help i will
appreciate.<BR><BR> Thanks<BR><BR>
<DIV class=gmail_quote>On Sun, Mar 14, 2010 at 12:50 PM, hossam <SPAN
dir=ltr><<A
href="mailto:hossam.elasrag@gmail.com">hossam.elasrag@gmail.com</A>></SPAN>
wrote:<BR>
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class=gmail_quote>Hi,<BR><BR>This is my first post to the mpi-forum. I have
a runtime problem related to MPI using MPICH2. I wonder if this is the
correct forum to post my problem.<BR>Please let me know so i can proceed
forward with my problem details.<BR><BR>Thanks<BR
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