[petsc-users] early convergence failure

[Daniel Arndt]

Hello everyone,

at the moment I'm trying to solve a Poisson problem with SIPG
stabilization and discontinuous finite elements. The matrix is
constructed in deal.II. When I try to solve this problem with PETSc's CG
solver and a BlockJacobi preconditioner or a BoomerAMG preconditioner
from the Hypre package I get this weird error message.

Exception on processing:
Iterative method reported convergence failure in step 3 with residual
1.50616
Aborting!

Since the solver is allowed to take 5000 steps this convergence failure
is clearly early. Did anyone encounter such an error before? What can
produce such an early convergence failure?

Thanks in advance,
Daniel