Samar : There are limitations for direct solvers. Do not expect any solver can be used on arbitrarily large problems. Since superlu_dist also crashes, direct solvers may not be able to work on your application. This is why I suggest to increase size incrementally. You may have to experiment other type of solvers.
Hong Hi Hong and Jed, > > Many thanks for replying. It would indeed be nice if the error messages > from MUMPS were less cryptic! > > 1) I have tried smaller matrices although given how my problem is set up > a jump is difficult to avoid. But a good idea > that I will try. > > 2) I did try various ordering but not the one you suggested. > > 3) Tracing the error through the MUMPS code suggest a rather abrupt > termination of the program (there should be more > error messages if, for example, memory was a problem). I therefore thought > it might be an interface problem rather than > one with mumps and turned to the petsc-users group first. > > 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 > crash would again indicate a common (memory?) problem. > > I'll try a few more things before asking the MUMPS developers. > > Thanks again for your help! > > Samar > > On Feb 24, 2014, at 11:47 AM, Hong Zhang <[email protected]> wrote: > > Samar: > The crash occurs in > >> ... >> [161]PETSC ERROR: Error in external library! >> [161]PETSC ERROR: Error reported by MUMPS in numerical factorization >> phase: INFO(1)=-1, INFO(2)=48 > > > for very large matrix, likely memory problem as you suspected. > I would suggest > 1. run problems with increased sizes (not jump from a small one to a very > large one) and observe memory usage using > '-ksp_view'. > I see you use '-mat_mumps_icntl_14 1000', i.e., percentage of estimated > workspace increase. Is it too large? > Anyway, this input should not cause the crash, I guess. > 2. experimenting with different matrix ordering -mat_mumps_icntl_7 <> (I > usually use sequential ordering 2) > I see you use parallel ordering -mat_mumps_icntl_29 2. > 3. send bug report to mumps developers for their suggestion. > > 4. try other direct solvers, e.g., superlu_dist. > > >> ... >> >> 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. >> >> 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 >> error would be very much appreciated. >> > > I do not know how to interpret this output file. mumps developer would > give you better suggestion on it. > I would appreciate to learn as well :-) > > Hong > > >
