Hi, Thanks for the information. I now increased the workspace by adding '-mat_mumps_icntl_14 100'
It works. However, the problem is, if I submit in 1 core I get the answer in 200 secs, but with 4 cores and '-mat_mumps_icntl_14 100' it takes 3500secs. My command line is: 'mpiexec -np 4 ./ex7 -f1 a2 -f2 b2 -eps_nev 1 -st_type sinvert -eps_max_it 5000 -st_ksp_type preonly -st_pc_type lu -st_pc_factor_mat_solver_package mumps -mat_mumps_icntl_14 100' Kindly let me know. Venkatesh On Sat, May 16, 2015 at 7:10 PM, David Knezevic <david.kneze...@akselos.com> wrote: > On Sat, May 16, 2015 at 8:08 AM, venkatesh g <venkateshg...@gmail.com> > wrote: > >> Hi, >> I am trying to solving AX=lambda BX eigenvalue problem. >> >> A and B are of sizes 3600x3600 >> >> I run with this command : >> >> 'mpiexec -np 4 ./ex7 -f1 a2 -f2 b2 -eps_nev 1 -st_type sinvert >> -eps_max_it 5000 -st_ksp_type preonly -st_pc_type lu >> -st_pc_factor_mat_solver_package mumps' >> >> I get this error: (I get result only when I give 1 or 2 processors) >> Reading COMPLEX matrices from binary files... >> [0]PETSC ERROR: --------------------- Error Message >> ------------------------------------ >> [0]PETSC ERROR: Error in external library! >> [0]PETSC ERROR: Error reported by MUMPS in numerical factorization phase: >> INFO(1)=-9, INFO(2)=2024 >> > > > The MUMPS error types are described in Chapter 7 of the MUMPS manual. In > this case you have INFO(1)=-9, which is explained in the manual as: > > "–9 Main internal real/complex workarray S too small. If INFO(2) is > positive, then the number of entries that are missing in S at the moment > when the error is raised is available in INFO(2). If INFO(2) is negative, > then its absolute value should be multiplied by 1 million. If an error –9 > occurs, the user should increase the value of ICNTL(14) before calling the > factorization (JOB=2) again, except if ICNTL(23) is provided, in which case > ICNTL(23) should be increased." > > This says that you should use ICTNL(14) to increase the working space size: > > "ICNTL(14) is accessed by the host both during the analysis and the > factorization phases. It corresponds to the percentage increase in the > estimated working space. When significant extra fill-in is caused by > numerical pivoting, increasing ICNTL(14) may help. Except in special cases, > the default value is 20 (which corresponds to a 20 % increase)." > > So, for example, you can avoid this error via the following command line > argument to PETSc: "-mat_mumps_icntl_14 30", where 30 indicates that we > allow a 30% increase in the workspace instead of the default 20%. > > David > > >