Hi everyone, I am wondering how I can run the direct solver in parallel. I can run my program in a single processor with direct linear solver by ./foo.out -ksp_type preonly -pc_type lu -pc_factor_mat_solver_package spooles However, when I try to run it with mpi: mpirun.openmpi -np 2 ./foo.out -ksp_type preonly -pc_type lu -pc_factor_mat_solver_package spooles I got error like this: [0]PETSC ERROR: --------------------- Error Message ------------------------------------ [0]PETSC ERROR: No support for this operation for this object type! [0]PETSC ERROR: Matrix type mpiaij symbolic LU! [0]PETSC ERROR: Libraries linked from /home/hazelsct/petsc-2.3.3/lib/linux-gnu-c-opt [0]PETSC ERROR: Configure run at Mon Jun 30 14:37:52 2008 [0]PETSC ERROR: Configure options --with-shared --with-dynamic --with-debugging=0 --useThreads 0 --with-mpi-dir=/usr/lib/openmpi --with-mpi-shared=1 --with-blas-lib=-lblas --with-lapack-lib=-llapack --with-umfpack=1 --with-umfpack-include=/usr/include/suitesparse --with-umfpack-lib="[/usr/lib/libumfpack.so,/usr/lib/libamd.so]" --with-superlu=1 --with-superlu-include=/usr/include/superlu --with-superlu-lib=/usr/lib/libsuperlu.so --with-spooles=1 --with-spooles-include=/usr/include/spooles --with-spooles-lib=/usr/lib/libspooles.so --with-hypre=1 --with-hypre-dir=/usr --with-babel=1 --with-babel-dir=/usr [0]PETSC ERROR: ------------------------------------------------------------------------ [0]PETSC ERROR: MatLUFactorSymbolic() line 2174 in src/mat/interface/matrix.c [0]PETSC ERROR: PCSetUp_LU() line 257 in src/ksp/pc/impls/factor/lu/lu.c ------------------------------------------------------- Would you like to tell me where I am doing wrong? I appreciate your help. Xiangdong