Thank you for you mention! Just a comment on the euclid in petsc， the bj parameter(forblock Jacobi） for euclid was set  but not allowed in the option，just add few code will enable the -bj option. Best, Gang ------------------ Original ------------------ From: Zhang, Hong <[email protected]> Date: Sat,Jan 16,2021 3:00 PM To: Chen Gang <[email protected]> Cc: petsc-dev <[email protected]>, cglwdm <[email protected]> Subject: Re: [petsc-dev] About parallel of ILU