Tmux Runbook

 Step 1: Install Tmux on the Server

SSH into your RunPod instance and run the following commands to update the package manager and install tmux: 

bash

# Update package lists
apt-get update

# Install tmux
apt-get install -y tmux

Step 2: Start a Persistent Session

Always launch a named session before starting any long-running command. Naming the session makes it easy to track and re-enter.

bash

# Syntax: tmux new -s <session_name>
tmux new -s training_session

Step 3: Execute and Detach

Run your script normally inside the tmux window.

1. Start your process:
   bash

   python3 train.py --epochs 100
   

   
   
2. Disconnect safely (Detach):
   To leave the script running in the background and return to your regular server terminal, press this exact key sequence:
   • Press and hold Ctrl + B at the same time.
   • Release both keys.
   • Press D on your keyboard. 

You will see a message like [detached (from session training_session)]. You can now safely close your terminal or close your laptop; the script will not stop. 

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Step 4: Reconnect and Monitor

If your connection drops, or if you want to check your progress hours later:

1. SSH back into your RunPod instance.
2. List active sessions to verify it is still running:
   bash

   tmux ls
   

   
   
3. Re-attach to your session:
   bash

   # Syntax: tmux attach -t <session_name>
   tmux attach -t training_session
   

   
   

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Step 5: Clean Up

Once your script finishes running completely, you should close the session to free up server resources.

• Option A (Inside the session): Type exit and press Enter.
• Option B (Outside the session): Run tmux kill-session -t training_session.

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Cheat Sheet Reference

Goal	Key / Command
Install Tmux	apt-get install -y tmux
Start Named Session	tmux new -s <name>
List All Sessions	tmux ls
Detach from Session	Ctrl + B then D
Re-attach to Session	tmux attach -t <name>
Kill/Delete Session	tmux kill-session -t <name>