On Sat, 10 Sep 2011, amrit poudel wrote: > All right, got it. I must specify -pc_type to lu if I want to use > mumps and there is no way around it. This basically means I will > need astronomical amount of memory :( as noted in my previous email.
Yes - direct solvers can need lot of memory. > [1]PETSC ERROR: Error reported by MUMPS in numerical factorization phase: > Cannot allocate required memory > 2022169721 megabytes As the message says - MUMPS needs that much memory to solve your problem. Your attempt to work arround 'lu' and to call mumps directly - and save memory is based on the false notion that 'lu' in PETSc is something different [from direct solver] - and comsumes its own memory. [which is incorrect] LU in PETSc is an iterface to direct solver implemneations. [who do their own factiorizations - and need memory for that work] Satish
