Mostly, I use SSH command to connect to my remote server. Unfortunately, today the power is gone and the Ethernet hub is turned off, so my SSH session was lost. What do you do if an important task is going on after losing your SSH session? Here is the simple tool called Tmux to keep a process running  after the SSH or Putty session lost.

Full article here:
Linux Troubleshooting: How To Keep A Process Running After Putty Or SSH Session Closed? (Unixmen)