Using “screen” to run simulations on a remote host

The suggested way to run your simulations on a remote host (let say for instance on ada-18) is to use screen, which allows you to:

• use multiple shell windows from a single SSH session
• keep a shell active even through network disruptions
• disconnect and re-connect to a shell sessions from multiple locations
• run a long running process without maintaining an active shell session.

Start screen

Enter in a terminal

screen

or – better – start a screen session by giving it a name (for instance “sim1”):

screen -S sim1

This is very useful if you are going to start several screen sessions on the same host.

Start a simulation

After you’ve started a screen session (see above) you will see a normal terminal prompt and at this point you can start your simulation:

./start_my_simulation_nr_1 with some parameters

Afterwards to disconnect from the screen session just type “Ctrl+a” and “d” (i.e. the control key and a lowercase “a” and then the lowercase “d”; d=disconnect).

Later you can re-connect to this screen session with the command:

screen -r

or – if you started screen with the “-S” option – with the command:

screen -r sim1

More information

See the man page of screen:

man screen

In particular read about the “screen commands”, those that begin with Ctrl+a.

Posted on 17-May-2023 by ISG D-MATH
in Computing