On Sat, May 16, 2015 at 8:08 AM, venkatesh g <[email protected]> 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
