[petsc-users] problems using MUMPS as a linear solver

[Dominik Szczerba]

I am using MUMPS as a linear solver in my custom non-linear procedure
(basically a loop).
I specify the following options:

-pc_type lu -pc_factor_mat_solver_package mumps -mat_mumps_icntl_4 3
-mat_mumps_icntl_28 2 -mat_mumps_icntl_29 2 -ksp_monitor_true_residual
-ksp_converged_reason -ksp_view

I have noticed, that this does not actually do what I expect: I just
want to unconditionally solve my system of equations with MUMPS, but I
see that it actually is only a preconditioner. Gmres is in charge,
performing iterations. I tried -ksp_max_it 1 but then I get divergence
because residue reduction is somehow very poor (?), which does not
make sense, because I expect the system be solved down to the epsilon.

So is it somehow possible to just solve my Ax=b with MUMPS?

Regards,
Dominik