[SOLVED] Reboot: Command Not Found in Linux

[SOLVED] Reboot: Command Not Found in Linux

Linux terminal showing the installation of reboot a command for system restarting

Are you struggling with restarting your Linux system from the command line? The ‘reboot’ command, akin to a trusty switch, can help you restart your system effortlessly. However, for beginners and even some experienced users, installing and using Linux commands can appear daunting. But have no fear, this guide has got you covered!

In this guide, we will navigate you through the process of installing and using the ‘reboot’ command in Linux. We will cover instructions for both APT package management systems like Debian and Ubuntu, and YUM-based systems such as CentOS and AlmaLinux. We will also delve into advanced topics like compiling from source and installing a specific version of the command. Finally, we will provide guidance on how to use the ‘reboot’ command and verify the correct version is installed.

So, let’s dive in and start mastering the ‘reboot’ command in Linux!

TL;DR: How Do I Install and Use the ‘reboot’ Command in Linux?

In most Linux distributions, the ‘reboot’ command comes pre-installed. You can verify this with, reboot --version. However, if you receive an error such as , reboot: command not found, you can install it via the systemd package and the commands: sudo apt install systemd or sudo yum install systemd. To use it, simply type sudo reboot in the terminal.

sudo reboot

This command will immediately restart your system. However, the ‘reboot’ command has more to it than just a simple restart. Continue reading for a more detailed guide on how to use the ‘reboot’ command effectively, including alternative installation methods and troubleshooting tips.

Mastering the ‘reboot’ Command: A Beginner’s Guide

The ‘reboot’ command in Linux is a powerful tool that allows you to restart your system directly from the command line. This command is handy in situations where you need to apply system updates, troubleshoot issues, or simply want to refresh your system.

Now, let’s delve into how you can install and use the ‘reboot’ command in your Linux system.

Installing ‘reboot’ with APT

If you’re using a Debian-based Linux distribution like Ubuntu, you can use the Advanced Packaging Tool (APT) to install the ‘reboot’ command. However, in most cases, the ‘reboot’ command comes pre-installed.

You can verify if the ‘reboot’ command is already installed by using the following command:

which reboot

If the ‘reboot’ command is installed, the output will display the path to the ‘reboot’ command.

# Output:

If the ‘reboot’ command is not installed, you can install it via the systemd package using:

 sudo apt install systemd

However, this is rarely needed as ‘reboot’ is usually part of the base system.

Installing ‘reboot’ with YUM

For CentOS, AlmaLinux, or other Red Hat-based distributions, the ‘reboot’ command is part of the ‘systemd’ package, which is included in the base install.

You can confirm if the ‘reboot’ command is installed using the ‘which’ command, similar to the APT method.

However if for some reason the command can not be found, you can install the systemd package with:

 sudo yum install systemd

Remember, the ‘reboot’ command is a powerful tool that can help you manage your Linux system effectively. By understanding how to install and use this command, you’re one step closer to mastering Linux administration.

Installing the ‘reboot’ Command from Source Code

For those who prefer to compile their own binaries or need a specific version of the ‘reboot’ command, you can compile it from source code. Here’s how you can do it:

# Download the source code
wget http://ftp.gnu.org/gnu/coreutils/coreutils-8.32.tar.xz

# Extract the tarball
tar -xvf coreutils-8.32.tar.xz

# Change to the source directory
cd coreutils-8.32

# Compile the source code
./configure && make

# Install the compiled binaries
sudo make install

This will install the ‘reboot’ command along with other GNU core utilities.

Installing Different Versions of the ‘reboot’ Command

Different versions of the ‘reboot’ command may have different features, bug fixes, or compatibility with certain systems. Here’s how you can install a specific version of the ‘reboot’ command:

From Source Code

To install a specific version from source code, you just need to download the specific version’s tarball. For example, to download version 8.30, you would replace ‘8.32’ with ‘8.30’ in the wget command above.

Using APT or YUM

To install a specific version using APT or YUM, you can specify the version number in the install command. However, not all versions may be available in the repositories.

# Using APT
sudo apt-get install coreutils=8.30-3ubuntu2

# Using YUM
sudo yum install coreutils-8.30-6.el7

In the commands above, replace ‘8.30-3ubuntu2’ or ‘8.30-6.el7’ with the version number you want to install.

VersionNotable Changes
8.32Latest stable release.
8.31Fixed a bug in chroot.
8.30Added the ‘whoami’ command.

Using the ‘reboot’ Command

You can use the ‘reboot’ command to restart your system immediately, schedule a reboot, or reboot into a different runlevel. Here are some examples:

# Reboot the system immediately
sudo reboot

# Schedule a reboot in 5 minutes
sudo shutdown -r +5

# Reboot into runlevel 1 (single-user mode)
sudo telinit 1

In the commands above, ‘shutdown -r +5’ schedules a reboot in 5 minutes, and ‘telinit 1’ reboots the system into single-user mode.

Verifying the Installation

You can verify that the ‘reboot’ command is installed correctly by checking its version number. Here’s how you can do it:

reboot --version

This command will output the version number of the ‘reboot’ command, confirming that it is installed correctly.

Exploring Alternatives to the ‘reboot’ Command

While the ‘reboot’ command is a straightforward tool for restarting your Linux system, there are alternative methods that offer more control and flexibility. Let’s explore some of these alternatives.

Using the ‘shutdown -r’ Command

The ‘shutdown -r’ command is a versatile tool that not only reboots your system but also allows you to schedule the reboot.

# Schedule a reboot in 10 minutes
sudo shutdown -r +10

In the command above, the ‘-r’ option tells ‘shutdown’ to reboot the system, and ‘+10’ schedules the reboot in 10 minutes. This gives you time to save your work or inform other users about the impending reboot.

Using the ‘systemctl reboot’ Command

The ‘systemctl’ command is part of the systemd system and service manager, which is used in many modern Linux distributions. It provides a ‘reboot’ command that works similarly to the standalone ‘reboot’ command.

# Reboot the system
sudo systemctl reboot

This command immediately reboots the system, just like ‘sudo reboot’. However, ‘systemctl’ also offers other commands for managing the system state, such as ‘poweroff’ to power off the system and ‘suspend’ to suspend the system.

Using the ‘init’ Command

The ‘init’ command, also known as ‘telinit’, changes the system’s runlevel. By changing the runlevel to 6, you can reboot the system.

# Reboot the system
sudo init 6

In the command above, ‘6’ is the runlevel for rebooting the system. This method is a bit more low-level and may not work on systems that use systemd instead of the traditional SysV init.

rebootSimple and straightforwardLimited options
shutdown -rCan schedule the rebootMore complex syntax
systemctl rebootWorks with systemdNot available on non-systemd systems
init 6Works with SysV initNot available on systemd systems

While the ‘reboot’ command is a simple and effective method for restarting your Linux system, these alternatives offer more control and flexibility. Depending on your needs and your system’s configuration, you might find one of these alternatives more suitable.

Overcoming Challenges with the ‘reboot’ Command

While the ‘reboot’ command is a powerful tool in Linux, you may encounter some issues while using it. Let’s discuss some common problems and their solutions.

Permission Denied

If you try to use the ‘reboot’ command without sufficient privileges, you’ll receive a ‘Permission denied’ error message.


# Output:
# reboot: Need to be root

In the example above, trying to execute the ‘reboot’ command as a non-root user results in a ‘Need to be root’ error. To overcome this, you can use the ‘sudo’ command to execute ‘reboot’ with root privileges.

sudo reboot

Command Not Found

If the ‘reboot’ command is not installed or not in the system’s PATH, you’ll receive a ‘Command not found’ error.


# Output:
# bash: reboot: command not found

In the example above, the system cannot find the ‘reboot’ command. To resolve this, you can install the ‘reboot’ command as described in the ‘Installation’ sections of this guide.

System Does Not Reboot

If the system does not reboot after using the ‘reboot’ command, it could be due to a problem with the system itself or a misconfiguration. In such cases, it’s best to consult the system logs for more information.

journalctl -b -1

In the command above, ‘journalctl -b -1’ displays the system log from the previous boot, which may contain error messages or warnings related to the failed reboot.

Remember, the ‘reboot’ command is a powerful tool, but like any tool, it can sometimes present challenges. By understanding these common issues and their solutions, you can use the ‘reboot’ command more effectively and troubleshoot any problems that arise.

Understanding the Fundamentals of System Rebooting in Linux

To fully grasp the importance and functionality of the ‘reboot’ command, it’s crucial to first understand the concept of system rebooting in Linux. Let’s dive into the fundamentals of system rebooting and why it’s essential in a Linux environment.

The Importance of System Rebooting in Linux

Rebooting is a crucial process in managing any operating system, including Linux. It helps in applying updates, resetting system state, and troubleshooting issues. In Linux, the ‘reboot’ command is a simple yet powerful tool that enables you to perform a system reboot directly from the command line.

sudo reboot

In the command above, ‘sudo’ is used to execute the ‘reboot’ command with root privileges, which is necessary as rebooting is a system-level operation. After executing the command, the system will immediately start the reboot process.

The Reboot Process in Linux

When you execute the ‘reboot’ command, the Linux system initiates a series of processes to safely restart the system. These include terminating running processes, unmounting filesystems, and finally, triggering a hardware reset.

ps -ef --forest

The command above displays the hierarchy of running processes. When the ‘reboot’ command is executed, these processes are terminated in an orderly manner to prevent data loss and system corruption.

System Runlevels

In Linux, different system states, known as runlevels, control the behavior of the system. For example, runlevel 0 is for shutdown, runlevel 1 is for single-user mode (used for system maintenance), and runlevel 6 is for rebooting.


The command above displays the current and previous runlevels. When the ‘reboot’ command is executed, the system switches to runlevel 6 to initiate the reboot process.

Understanding the concepts underlying the ‘reboot’ command and the importance of proper system rebooting in Linux will enhance your Linux administration skills and help you use the ‘reboot’ command more effectively.

Broadening Your Linux Mastery: System Rebooting and Beyond

Mastering the ‘reboot’ command and understanding system rebooting are essential skills in Linux administration. However, the world of Linux extends far beyond just rebooting. System administration and security, in particular, are fields where understanding system rebooting is just the tip of the iceberg.

The Role of System Rebooting in Administration and Security

System rebooting plays a crucial role in both administration and security. For administrators, the ability to reboot systems remotely allows for easy management of updates and system maintenance. In terms of security, a reboot can help ‘clean’ the system by terminating potentially malicious processes.

Exploring Other System Commands: Shutdown and Runlevels

In addition to the ‘reboot’ command, Linux offers other commands for managing system states. For instance, the ‘shutdown’ command allows you to power off the system or schedule a shutdown. You can also use the ‘init’ command to change the system’s runlevel, which controls the services and processes that are run at startup.

# Shutdown the system
sudo shutdown -h now

# Change to runlevel 3 (multi-user mode)
sudo init 3

In the commands above, ‘shutdown -h now’ immediately powers off the system, and ‘init 3’ changes the system to multi-user mode, which is often used for servers.

Further Resources for Mastering Linux Commands

To deepen your understanding of Linux and its various commands, here are some resources that you might find useful:

  1. The Linux Command Line: A Complete Introduction – This book provides a comprehensive introduction to the Linux command line, including basic and advanced commands.

  2. Linux Administration: A Beginner’s Guide – This guide covers various aspects of Linux administration, including system management, network administration, and security.

  3. Advanced Linux Programming – This website offers resources for advanced Linux programming, including system programming, process management, and inter-process communication.

Remember, mastering Linux is a journey. By exploring these resources and practicing regularly, you can enhance your skills and become a proficient Linux user.

Wrapping Up: Becoming Proficient in Using the ‘reboot’ Command in Linux

In this comprehensive guide, we’ve navigated the ins and outs of the ‘reboot’ command in Linux, a powerful tool for system administration.

We embarked with the basics of installing and using the ‘reboot’ command in Linux, covering both APT and YUM package management systems. We then ventured into more advanced territory, discussing how to install the ‘reboot’ command from source code and how to install different versions of the command. We also delved into the various ways to use the ‘reboot’ command, including scheduling a reboot and rebooting into a different runlevel.

Along the way, we tackled common issues you might encounter when using the ‘reboot’ command, such as ‘Permission denied’ and ‘Command not found’, providing you with solutions to overcome these challenges. We also explored alternative methods for rebooting a Linux system, such as using the ‘shutdown -r’ and ‘systemctl reboot’ commands, and changing the system’s runlevel with the ‘init’ command.

rebootSimple and straightforwardLimited options
shutdown -rCan schedule the rebootMore complex syntax
systemctl rebootWorks with systemdNot available on non-systemd systems
init 6Works with SysV initNot available on systemd systems

Whether you’re just starting out with Linux or you’re a seasoned system administrator, we hope this guide has helped you master the ‘reboot’ command and its alternatives. With these tools at your disposal, you’re well equipped to manage your Linux system effectively. Happy rebooting!