How to Use tmux: Managing Multiple Terminals and Keeping Sessions Alive When SSH Drops – ITFROMZERO

Table of Contents

The Problem: Opening 10 Terminal Tabs Only to Lose Them All When SSH Disconnects

When I first started working with Linux servers, I had a habit of opening dozens of terminal tabs to monitor logs, run commands, and edit files — one tab per task. It looked impressive but was actually a complete mess. Then one day I SSHed into a VPS to deploy something, and right in the middle of the process, the network went down. The connection dropped, the build process died, and I had to start over from scratch. It was painful.

That build took 20 minutes. The second attempt ran into different errors because the environment was left in a broken state. After that incident, I learned an expensive lesson — and tmux is now the first thing I install on any new server.

Standard Terminals: Two Fatal Weaknesses

There are two core problems that standard terminals (or plain SSH) simply cannot solve:

No persistent sessions: When an SSH connection drops (network outage, laptop sleep, timeout), every running process gets killed immediately.
No window management: Multiple SSH tabs mean multiple separate connections, with no way to get an overview or quickly switch between tasks.

Juniors often reach for nohup or & to run things in the background — fine for one or two simple commands. But when projects get more complex (monitoring logs, running a server, and editing configs simultaneously), nohup doesn’t cut it.

Comparing Your Options

Option 1: Use `nohup` or `screen`

nohup keeps a process running after logout, but gives you no interface to interact with it again. screen is better — it creates persistent sessions with attach/detach support — but the interface feels dated, the shortcuts are hard to remember, and it lacks tmux’s split-pane capabilities.

Option 2: Open Multiple Parallel SSH Connections

It works, but wastes resources. An unstable network will still wipe everything out at once. It doesn’t address the root problem.

Option 3: Use tmux

tmux (terminal multiplexer) lets you:

Create sessions that persist independently of the SSH connection
Split a single terminal window into multiple panes
Switch quickly between windows and sessions
Detach and reattach at any time, from any machine

Mastering tmux Step by Step

Step 1: Install tmux

On most Linux distros, tmux is available in the package manager:

# Ubuntu / Debian
sudo apt update && sudo apt install tmux -y

# CentOS / RHEL / Fedora
sudo dnf install tmux -y

# Arch Linux
sudo pacman -S tmux

# Check version
tmux -V

tmux 3.x and above supports mouse input and includes significant improvements. Run tmux -V — if you see tmux 3.2a or higher, you’re good to go.

Step 2: Understand tmux’s Three-Level Structure

Before typing any commands, get these three concepts straight:

Session: The top-level container. A session can hold multiple windows and persists even when you detach.
Window: Equivalent to a tab in a terminal. Each window occupies the full screen.
Pane: A window can be split into multiple panes, each acting as an independent terminal.

Think of it this way: a Session is an office building, Windows are individual rooms, and Panes are the desks inside each room.

Step 3: Basic Commands from Outside tmux

# Create a new session (unnamed)
tmux

# Create a session with a specific name (recommended)
tmux new-session -s deploy
tmux new -s monitoring   # shorthand

# List all running sessions
tmux ls

# Attach to a session by name
tmux attach -t deploy
tmux a -t deploy         # shorthand

# Attach to the most recent session
tmux a

# Kill a session
tmux kill-session -t deploy

Step 4: Shortcuts Inside tmux

Every tmux command starts with the prefix key — defaulting to Ctrl + b. Press the prefix, release it, then press the command key. Do not hold all three keys simultaneously.

Example: to create a new window, press Ctrl+b, release, then press c.

Session Management:

Ctrl+b d        # Detach from session (session keeps running in background)
Ctrl+b $        # Rename current session
Ctrl+b s        # View session list (select to switch)

Window Management:

Ctrl+b c        # Create a new window
Ctrl+b ,        # Rename current window
Ctrl+b n        # Switch to next window
Ctrl+b p        # Switch to previous window
Ctrl+b 0-9      # Jump directly to window 0, 1, 2...
Ctrl+b w        # View window list to select
Ctrl+b &        # Close current window (with confirmation)

Pane Management:

Ctrl+b %        # Split screen vertically
Ctrl+b "        # Split screen horizontally
Ctrl+b arrow    # Move between panes
Ctrl+b z        # Zoom current pane (toggle fullscreen)
Ctrl+b x        # Close current pane (with confirmation)
Ctrl+b q        # Show pane numbers
Ctrl+b {        # Move pane to the left
Ctrl+b }        # Move pane to the right

Step 5: A Real-World Deploy Scenario

Here’s how I typically deploy a Node.js application to a VPS:

# SSH into the server
ssh user@vps-ip

# Create a session named 'deploy'
tmux new -s deploy

# Split pane: run deploy command on the left, watch logs on the right
Ctrl+b %

# Left pane: run the deploy script
git pull origin main && npm install && pm2 restart app

# Switch to right pane (Ctrl+b →)
# Right pane: watch logs in real time
pm2 logs app --lines 50

# If the network drops, SSH back in and reattach to the old session
tmux a -t deploy
# Everything is still there!

I once deployed an app with a 15-minute build pipeline. The network cut out mid-way, I SSHed back in, attached to the session — the build was still running, the logs were all there, nothing was lost.

Step 6: Customize tmux with a Config File

The config file lives at ~/.tmux.conf. The minimal config below is a solid starting point:

# Change prefix from Ctrl+b to Ctrl+a (more familiar for GNU screen users)
# set-option -g prefix C-a
# unbind C-b
# bind C-a send-prefix

# Enable mouse — scroll and click to select panes
set -g mouse on

# Number windows starting from 1 instead of 0 (more natural on the keyboard)
set -g base-index 1
setw -g pane-base-index 1

# Increase scrollback buffer to 5000 lines (default is 2000)
set -g history-limit 5000

# Status bar shows hostname and time
set -g status-right '%Y-%m-%d %H:%M'
set -g status-right-length 30

# Reload config without restarting tmux
bind r source-file ~/.tmux.conf \; display "Config reloaded!"

After editing, reload the config with:

# Inside tmux, press:
Ctrl+b r

# Or from outside:
tmux source-file ~/.tmux.conf

Step 7: Multi-Session Workflow for Multiple Projects

Each project or server should have its own session — organized this way, Ctrl+b s brings up a handy session selection menu:

# One session per project/server
tmux new -s itfromzero    # Main blog
tmux new -s monitoring    # Server monitoring
tmux new -s staging       # Staging environment

# Get an overview of everything
tmux ls
# itfromzero: 3 windows (created Fri Feb 28 09:00:00 2026)
# monitoring: 1 windows (created Fri Feb 28 08:30:00 2026)
# staging: 2 windows (created Fri Feb 28 10:15:00 2026)

# Switch between sessions from inside tmux
Ctrl+b s   # Show session selection menu

Wrapping Up

Around 10 shortcuts will cover 80% of your daily work. No need to learn everything at once.

Suggested learning path:

Install tmux, create a named session
Practice detaching (Ctrl+b d) and reattaching (tmux a -t name)
Learn pane splitting (Ctrl+b % and Ctrl+b ")
Add set -g mouse on to ~/.tmux.conf to enable mouse support
Gradually explore more features as you need them

The most effective way to learn is to use tmux in your actual work — the next time you SSH into a server, open tmux right away. After a few weeks, the shortcuts will become muscle memory and you won’t need to glance at a cheatsheet anymore.