Thanks Barry, some 'nan's in the rhs matrix caused the issue strangely when cpu numbers gets larger than 4.
Best, Mohammad On Wed, Jan 10, 2018 at 5:30 PM, Smith, Barry F. <[email protected]> wrote: > > You can also run with -fp_trap to find where the nan/inf first appears > as well as run with -ksp_monitor to see what is happening before the tragedy > > Barry > > > > On Jan 10, 2018, at 3:41 PM, Mohammad R. Gohardoust < > [email protected]> wrote: > > > > Hi, > > > > I hope you are doing well. I am Mohammad, a PhD student of environmental > sciences at the University of Arizona. > > > > I do appreciate any help that can shed some light on the issue I have: > recently I have added a feature to an existing parallel code called > 'parswms' which solves water and solute transport in soils. The code uses > MPI and parmetis for the parallelization purposes and petsc package > (KSPSolve) for solving linear systems. I have it installed on the UofA HPC > : the issue is that it works well if the number of CPUs are up to 4! but > when I add to this number the numerical linear solver (here it is 'KSPCGS') > stops with the error of 'KSP_DIVERGED_NANORINF'. > > > > Would you mind please giving me some hints, suggestions or resources in > this regard? > > > > > > Best Regards, > > Mohammad > > > > > > > >
