🐥 Running long-lived SSH commands with tmux

When working on a remote Linux server over SSH, it's common to run long-running commands like database migrations, backups, builds, or batch processing. One major problem: if your SSH connection drops, so does your command — unless you plan ahead.

This is where tmux becomes an invaluable tool.

tmux is a terminal multiplexer. It allows you to start a terminal session, run processes inside it, detach at any time, and later reattach — even after disconnecting from SSH. Your command keeps running in the background as if nothing happened.

1. SSH into the server

   ssh user@your-server
   

2. Start a new tmux session

   tmux new -s mysession
   

   You’re now inside a named tmux session called mysession. Everything you do inside this session will continue running even if your SSH connection drops.

3. Run your long-lived command

   ./my-long-script.sh
   

   Or any other long-running task.

4. Detach from tmux (leave it running) by pressing:

   Ctrl + b, then d
   

   You’ll be back at the normal shell, and your tmux session will continue running in the background.

5. After reconnecting to the server, you can reconnect to the session:

   tmux attach -t mysession
   

   Your session will be exactly as you left it.

To list all tmux sessions:

tmux ls

To kill a session:

tmux kill-session -t mysession