Can you split the computation into several parts such that the matrix you 
desire is a sum?

  A = A_1 + A_2 + A_3 + ...

Then you can create and write each of the matrices A_i separately
(perhaps in parallel jobs) and sum them later.

"Pham, Dung Ngoc" <[email protected]> writes:

> Dear Petsc developers and Users,
>
> I am constructing a very large matrices (~5,000,000*5,000,000) for a 
> generalized eigenvalue problem in MPIAIJ format across multiple nodes. The 
> program is to be run on a shared HPC cluster using Slurm workload manager. 
> Due to multiple loops and calculations needed, the matrix construction time 
> is long (may span for more than a week).
>
> Hence, I am trying to see if I can implement checkpoints into the codes, so 
> that the matrix can be constructed partially through multiple job 
> submissions, each job picking up from where the previous one left until the 
> matrix is fully built and we can write the global matrix into a binary file 
> for further eigenvalue analysis. My questions are:
> Does Petsc MPIAIJ format is amenable to such check points?
> If so, are there any subroutines/functions that I can start with?
>
> I appreciate any comments/suggestions.
>
> Thank you,
> D. N. Pham

Reply via email to