Linux suspend Command with Practical Examples

Introduction

In this lab, you will learn how to use the Linux suspend command to suspend and resume your system, as well as manage different power states. You will explore the Suspend to RAM (S3) and Suspend to Disk (S4) states, and understand how to use the systemctl suspend and systemctl hibernate commands to put the system into these low-power states. By the end of this lab, you will be able to effectively manage your system's power consumption and quickly resume your work from a suspended state.

Linux Commands Cheat Sheet

Understand the Linux suspend Command

In this step, we will explore the Linux suspend command, which allows you to suspend the system to RAM or disk. The suspend command puts the system into a low-power state, preserving the current state of the system in memory or on disk, so that you can quickly resume your work later.

First, let's understand the different power states available in Linux:

• Suspend to RAM (S3): In this state, the system's RAM is kept powered on, allowing for a quick resume, but the CPU and other components are powered down. This is the fastest way to resume the system.
• Suspend to Disk (S4) (also known as Hibernate): In this state, the system's state is saved to the disk, and the system is powered off completely. This takes longer to resume, but it preserves the system state even when the power is lost.

Now, let's explore how to use the suspend command:

sudo systemctl suspend

Example output:

[sudo] password for labex:

The systemctl suspend command puts the system into the Suspend to RAM (S3) state.

To suspend the system to disk (hibernate), use the following command:

sudo systemctl hibernate

Example output:

[sudo] password for labex:

The systemctl hibernate command puts the system into the Suspend to Disk (S4) state.

To resume the system from a suspended state, simply press the power button or any other key on the keyboard.

Suspend and Resume the System Using the suspend Command

In this step, we will learn how to suspend and resume the system using the suspend command.

First, let's suspend the system to RAM:

sudo systemctl suspend

Example output:

[sudo] password for labex:

The system is now in the Suspend to RAM (S3) state. To resume the system, simply press the power button or any other key on the keyboard.

Next, let's suspend the system to disk (hibernate):

sudo systemctl hibernate

Example output:

[sudo] password for labex:

The system is now in the Suspend to Disk (S4) state. To resume the system, press the power button.

You can also use the pm-suspend and pm-hibernate commands to suspend and hibernate the system, respectively. These commands are part of the pm-utils package, which provides a set of tools for power management.

sudo pm-suspend

Example output:

[sudo] password for labex:

sudo pm-hibernate

Example output:

[sudo] password for labex:

The pm-suspend and pm-hibernate commands provide more fine-grained control over the power management process, but the systemctl suspend and systemctl hibernate commands are generally more convenient to use.

Manage Power States with the suspend Command

In this step, we will explore how to manage the different power states of the system using the suspend command.

First, let's check the current power state of the system:

sudo systemctl status suspend.target

Example output:

● suspend.target - Suspend
     Loaded: loaded (/usr/lib/systemd/system/suspend.target; static; vendor preset: enabled)
     Active: inactive (dead)

The output shows that the system is currently in the "inactive" state, meaning it is not in the Suspend to RAM (S3) state.

To put the system into the Suspend to RAM (S3) state, use the following command:

sudo systemctl suspend

Example output:

[sudo] password for labex:

The system is now in the Suspend to RAM (S3) state. To resume the system, simply press the power button or any other key on the keyboard.

You can also put the system into the Suspend to Disk (S4) state using the systemctl hibernate command:

sudo systemctl hibernate

Example output:

[sudo] password for labex:

The system is now in the Suspend to Disk (S4) state. To resume the system, press the power button.

Additionally, you can use the pm-suspend and pm-hibernate commands to manage the power states:

sudo pm-suspend

sudo pm-hibernate

These commands provide more fine-grained control over the power management process, but the systemctl suspend and systemctl hibernate commands are generally more convenient to use.

Summary

In this lab, we learned about the Linux suspend command, which allows you to suspend the system to RAM (S3) or disk (S4, also known as Hibernate). We explored the different power states available in Linux and how to use the systemctl suspend and systemctl hibernate commands to suspend the system to RAM and disk, respectively. We also learned how to resume the system from a suspended state by simply pressing the power button or any other key on the keyboard.

Linux Commands Cheat Sheet