No retyping of passwords for computerclusters

config

ControlMaster auto
ControlPath ~/.ssh/control:%h:%p:%r

Host server1
    User username_on_server1
    HostName server1.com
    
Host server2
    User username_on_server2
    HostName server2.com

silent_ssh

#!/bin/bash
# Opens ssh sessions to be picked up by ControlMaster in ~/.ssh/config during the day
# -f forks to the background
# -N no commands to be executed on remote computer
# -o Specify ssh options
for computer in server1 server2; do
    printf "\n \n $computer \n \n"
    ssh -f $computer -N -o 'ServerAliveInterval 300' -o 'ServerAliveCountMax 100'
done

This is a minimal example of how to set up your ssh to not retype your passwords when often sshing to computer clusters from Unix.
Speak with the administrators of the remote servers if they allow this:

1. Append the snippet of the file config to ~/.ssh/config/
2. Put silent_ssh to a directory which is in PATH and make it executable.
3. Replace the names of server1, username_on_server1... with the actual names.

If you now execute silent_ssh it creates background processes of ssh connections to the remote servers.
Every time you reconnect to the server the ControlMaster will reuse the existing ssh connection.
This includes other ssh based services like scp, sftp or rsync.

Because of the options -o 'ServerAliveInterval 300' -o 'ServerAliveCountMax 100' you have to reexecute silent_ssh approximately every 8 hours.