Dear Mohammad, Thank you for your email! Could you provide more details on the error message that you are receiving? I have been mostly running parallel simulations with the incompressible solver in nektar++ and when I am changing the number of processors from one simulation to another, I never had any issues restarting a parallel simulation. Kind regards, Alexandra From: nektar-users-bounces@imperial.ac.uk <nektar-users-bounces@imperial.ac.uk> On Behalf Of m.r.rouhanian@ut.ac.ir Sent: 20 November 2022 11:48 To: nektar-users@imperial.ac.uk Subject: [Nektar-users] restart a solver in parallel This email from m.r.rouhanian@ut.ac.ir <mailto:m.r.rouhanian@ut.ac.ir> originates from outside Imperial. Do not click on links and attachments unless you recognise the sender. If you trust the sender, add them to your safe senders list <https://spam.ic.ac.uk/SpamConsole/Senders.aspx> to disable email stamping for this address. Dear all; When solving a problem in parallel with a restart file( e.g. restart.rst) as an initial condition I will encounter an error. I am using compressed binary output to solve the problem in parallel. I think this is because the .xml file depends on the number of cores converted to a smaller domain for each processor. However, the restart file contains field data for the entire domain. How can I restart a solver in parallel? Any comments would be appreciated. Best regards, Mohammad