Thanks, Matt, that option works perfectly, and explains the -ksp_view output.
Much appreciated! Matt... On Fri, Jul 6, 2018 at 6:25 PM, Matthew Knepley <[email protected]> wrote: > Default Case (zeropivot is 2.22045E-14): >> mpiexec -n 1 ... >> ==> ksp fails due to pcReason = PC_FACTOR_NUMERIC_ZEROPIVOT >> >> Reduced pivot case, n = 1: >> mpiexec -n 1 ... -pc_factor_zeropivot 1E-15 >> ==> runs successfully >> >> Reduced pivot case, n > 1: >> mpiexec -n 2 .. -pc_factor_zeropivot 1E-15 >> ==> ksp fails due to pcReason = PC_SUBPC_ERROR >> > > Okay, what is likely happening is that your preconditioner is actually > Block-Jacobi/LU > instead of parallel LU. Thus you would need > > -sub_pc_factor_zeropivot 1e-15 > >
