<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Hi Hong and Jed,</div><div><br></div><div>Many thanks for replying. It would indeed be nice if the error messages from MUMPS were less cryptic!</div><div><br></div><div>1) I have tried smaller matrices although given how my problem is set up a jump is difficult to avoid. But a good idea </div><div>that I will try.</div><div><br></div><div>2) I did try various ordering but not the one you suggested.</div><div><br></div><div>3) Tracing the error through the MUMPS code suggest a rather abrupt termination of the program (there should be more </div><div>error messages if, for example, memory was a problem). I therefore thought it might be an interface problem rather than </div><div>one with mumps and turned to the petsc-users group first. </div><div><br></div><div>4) I've tried superlu_dist but it also crashes (also unclear as to why) at which point I decided to try mumps. The fact that both </div><div>crash would again indicate a common (memory?) problem.</div><div><br></div><div>I'll try a few more things before asking the MUMPS developers.</div><div><br></div><div>Thanks again for your help!</div><div><br></div><div>Samar</div><div><br></div><div><div>On Feb 24, 2014, at 11:47 AM, Hong Zhang <<a href="mailto:hzhang@mcs.anl.gov">hzhang@mcs.anl.gov</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div dir="ltr">Samar:<div>The crash occurs in <div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
...<br>
[161]PETSC ERROR: Error in external library!<br>
[161]PETSC ERROR: Error reported by MUMPS in numerical factorization phase: INFO(1)=-1, INFO(2)=48</blockquote><div> </div><div>for very large matrix, likely memory problem as you suspected. </div><div>I would suggest </div>
<div>1. run problems with increased sizes (not jump from a small one to a very large one) and observe memory usage using</div><div>'-ksp_view'.</div><div> I see you use '-mat_mumps_icntl_14 1000', i.e., percentage of estimated workspace increase. Is it too large?</div>
<div> Anyway, this input should not cause the crash, I guess.</div><div>2. experimenting with different matrix ordering <span style="font-family:arial,sans-serif;font-size:13px">-mat_mumps_icntl_7 <> (I usually use sequential ordering 2) </span></div>
<div><span style="font-family:arial,sans-serif;font-size:13px"> I see you use parallel ordering -</span>mat_mumps_icntl_29 2.</div><div>3. send bug report to mumps developers for their suggestion.<br></div><div><br></div>
<div>4. try other direct solvers, e.g., superlu_dist.</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
…<br>
<br>
etc etc. The above error I can tell has something to do with processor 48 (INFO(2)) and so forth but not the previous one.<br>
<br>
The full output enabled with -mat_mumps_icntl_4 3 looks as in the attached file. Any hints as to what could be giving this<br>
error would be very much appreciated.<br></blockquote><div> </div><div>I do not know how to interpret this output file. mumps developer would give you better suggestion on it.</div><div>I would appreciate to learn as well :-)</div>
<div><br></div><div>Hong</div></div></div></div></div>
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