Working in a Linux terminal often means managing multiple tasks at the same time. You might be monitoring logs, editing configuration files, running long processes, or connecting to several remote servers. Opening multiple terminal windows is one option, but it quickly becomes difficult to manage.
This is where tmux becomes useful. tmux is a terminal multiplexer that allows you to create multiple terminal sessions, split your screen into panes, and keep applications running even after disconnecting from an SSH session. It is lightweight, reliable, and available in virtually every Linux distribution.
This guide covers the installation, initial configuration, and everyday usage of tmux with practical examples that you can immediately apply.
What Is tmux?
tmux (Terminal Multiplexer) allows multiple terminal sessions to exist inside a single terminal window. Instead of opening several terminal applications, you can organize everything into sessions, windows, and panes.
Some of its most useful features include:
- Persistent terminal sessions;
- Horizontal and vertical pane splitting;
- Multiple windows inside one session;
- Session sharing between users;
- Easy navigation using keyboard shortcuts;
- Low resource consumption.
One of the biggest advantages is that processes continue running even if your SSH connection drops.
Installing tmux
Most Linux distributions include tmux in their official repositories:
Ubuntu and Debian
sudo apt update
sudo apt install tmux
Fedora
sudo dnf install tmux
CentOS 8, Rocky Linux, AlmaLinux
sudo dnf install tmux
For older CentOS versions:
sudo yum install tmux
Arch Linux
sudo pacman -S tmux
After installation, verify the installed version:
tmux -V
Example output:
tmux 3.5a
Starting Your First Session
Launch tmux by running:
tmux
A new session starts immediately. You’ll notice a status bar at the bottom of the terminal showing information about the current session.
To create a named session:
tmux new -s development
Naming sessions makes them easier to identify when multiple sessions are active.
Understanding tmux Concepts
tmux is organized into three main components. Let’s talk about them:
Sessions
A session is the top-level container. You can have separate sessions for different projects.
Examples:
tmux new -s webserver
tmux new -s database
tmux new -s monitoring
Windows
Each session contains one or more windows. Think of windows as tabs in a browser.
Create a new window:
Ctrl+b c
Switch between windows:
Ctrl+b n
Go to the previous window:
Ctrl+b p
List all windows:
Ctrl+b w
Panes
Windows can be divided/splited into multiple panes.
Split vertically:
Ctrl+b %
Split horizontally:
Ctrl+b "
Move between panes:
Ctrl+b Arrow Key
Resize a pane:
Ctrl+b Ctrl+Arrow Key
This layout allows you to monitor logs, edit files, and execute commands simultaneously without leaving the current session.
Detaching and Reattaching Sessions
One of tmux’s strongest features is session persistence.
To detach from a running session:
Ctrl+b d
The session continues running in the background.
List available sessions:
tmux ls
Example:
development: 2 windows
monitoring: 1 window
Reconnect to a session:
tmux attach -t development
Or simply:
tmux a
if only one session exists.
Closing Sessions
To terminate the current session:
exit
Repeat until every pane is closed.
Alternatively:
tmux kill-session -t development
To terminate all running sessions:
tmux kill-server
⚠️ Use this carefully because it closes every tmux session currently running.
Basic Configuration
tmux reads its configuration from:
~/.tmux.conf
If the file does not exist, create it:
touch ~/.tmux.conf
Here is a practical starting configuration:
set -g mouse on
setw -g mode-keys vi
set -g history-limit 10000
set -g base-index 1
setw -g pane-base-index 1
bind r source-file ~/.tmux.conf \; display-message "Configuration reloaded"
This configuration provides several improvements:
- Enables mouse support (you can use your mouse inside the tmux session);
- Uses Vim-style navigation in copy mode;
- Increases scrollback history;
- Starts numbering windows at 1 instead of 0;
- Allows configuration reloading without restarting tmux.
Reload the configuration after saving:
Ctrl+b r
or
tmux source-file ~/.tmux.conf
Useful Keyboard Shortcuts
Most tmux commands begin with the default prefix:
Ctrl+b
Some shortcuts worth memorizing (or you can use this table as your reference):
| Shortcut | Action |
|---|---|
| Ctrl+b c | Create new window |
| Ctrl+b n | Next window |
| Ctrl+b p | Previous window |
| Ctrl+b % | Split vertically |
| Ctrl+b “ | Split horizontally |
| Ctrl+b Arrow | Move between panes |
| Ctrl+b x | Close current pane |
| Ctrl+b d | Detach session |
| Ctrl+b z | Toggle pane zoom |
| Ctrl+b , | Rename window |
| Ctrl+b $ | Rename session |
Learning just these shortcuts covers most day-to-day workflows.
Running Long Processes Safely
One common use case is running commands that take several hours.
For example:
rsync -av /backup remote:/storage
or
tar -czf archive.tar.gz large_directory/
If your SSH connection drops, these commands continue running inside tmux.
After reconnecting:
ssh server
Then:
tmux attach
Your session returns exactly where you left it.
Working Efficiently with Multiple Panes
A practical layout for system administration might look like this, for example:
- Pane 1: SSH session
- Pane 2:
htop - Pane 3:
tail -f /var/log/syslog - Pane 4: Text editor
This arrangement allows you to monitor system activity while making configuration changes without switching applications.
Copy Mode
tmux includes its own scrollback buffer.
Enter copy mode:
Ctrl+b [
Navigation becomes similar to Vim when mode-keys vi is enabled.
Useful keys:
k— Move upj— Move down/— SearchSpace— Start selectionEnter— Copy selectionq— Exit copy mode
This is especially useful when reviewing lengthy command output.
Common Troubleshooting
“command not found”
tmux is probably not installed.
Verify:
which tmux
If nothing is returned, install it using your distribution’s package manager.
Cannot reconnect to a session
Check existing sessions:
tmux ls
If no sessions appear, the previous session was likely closed.
Mouse does not work
Ensure your configuration includes:
set -g mouse on
Reload the configuration afterward.
Cannot Copy Text from tmux to the System Clipboard
A common source of confusion is selecting text inside tmux and discovering that it cannot be pasted into applications such as Notepad, VS Code, or another terminal window.
This usually happens because tmux keeps its own copy buffer, which is separate from your operating system’s clipboard.
If you simply need to copy text to another pane or window inside tmux, use copy mode:
Ctrl+b [
Select the text and press Enter to copy it into tmux’s internal buffer.
To integrate tmux with the system clipboard, install a clipboard utility.
On Debian and Ubuntu:
sudo apt install xclip
or
sudo apt install xsel
On Fedora:
sudo dnf install xclip
Then add the following line to your ~/.tmux.conf:
set -s set-clipboard on
Reload the configuration:
tmux source-file ~/.tmux.conf
Keep in mind that clipboard integration only works when a graphical clipboard is available. If you’re connected to a headless Linux server over SSH, tmux cannot access the clipboard on your local computer. In that case, the simplest solution is often to use your terminal emulator’s own text selection, which usually copies directly to the local clipboard.
Final Thoughts
tmux is one of the most valuable command-line tools available for Linux users, especially system administrators, developers, and anyone who regularly works over SSH. Once you become comfortable with sessions, windows, and panes, it significantly reduces the need to juggle multiple terminal windows while making long-running tasks much safer.
Start with the basic commands covered in this guide, create a simple ~/.tmux.conf, and gradually incorporate more shortcuts into your daily workflow. After a few days of regular use, managing terminal sessions without tmux will likely feel far less efficient.
