How to Increase Swap Space in Linux

In the realm of Linux, we occasionally face a situation where our systems become sluggish due to an overload of complex processes. This is where our digital savior, the ‘Swap Space,’ steps in. But first, let’s try to get a grasp on what swap space is.

Swap space is essentially a region on your hard disk that serves as an overflow for your system’s RAM. When your system’s physical memory becomes fully occupied, some of the infrequently accessed data is shifted into the swap space, a process creatively dubbed ‘swapping’. Swap space is, therefore, analogous to a traffic officer guiding the surplus cars of data to another lane when the main route is jam-packed.

Let’s imagine you are running an extensive machine learning model, and your system’s RAM is brimming with data. In such a scenario, the system moves some of the lesser-used data from RAM to the swap space, creating room for your active processes to run smoothly. It’s like decluttering your workspace to focus on an important task at hand.

We need to know our starting point before embarking on the journey to increase swap space. How much swap space does your system currently have? This information can be quickly obtained by entering the following command into the Linux terminal:

free -m

Example output what you may see in a Linux terminal:

This command will output your system’s total, used, and free swap space, measured in megabytes.

Assuming you’ve checked your current swap space, let’s explore different paths to increase it.

Method 1: Using the fallocate Command

The fallocate command is a tool that quickly generates a file of a specified size. It’s like a magician conjuring a rabbit out of a hat – but in our case, it’s a swap file out of thin air. Here are the steps to utilize this command:

# Create a new swap file
sudo fallocate -l 1G /swapfile

# Change the file permissions to secure it
sudo chmod 600 /swapfile

# Transform the file into swap space
sudo mkswap /swapfile

The above commands first create a swap file of size 1GB, secure it with appropriate permissions, and finally set it up as swap space.

Method 2: Using the dd Command

The ‘dd’ command is another powerful tool in the Linux arsenal. It’s somewhat similar to the fallocate command but comes with its unique twists. Here’s how to use this command to increase swap space:

# Create a new swap file
sudo dd if=/dev/zero of=/swapfile bs=1024 count=1048576

# Modify the file permissions for security
sudo chmod 600 /swapfile

# Turn the file into swap space
sudo mkswap /swapfile

In this example, we create a swap file using the dd command, secure it, and transform it into swap space.

Remember that the above methods will create a swap space that will last until the next system reboot. If you want to make the swap file persistent across reboots, you will need to add it to the /etc/fstab file:

echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab

After setting up the swap space, you’ll want to activate it with the following command:

At this point, you’ve successfully increased your swap space! You can verify it by using the ‘free -m’ command again. But remember, with great power comes great responsibility. So regularly monitor your new swap space to ensure your system performance stays smooth.

Monitoring Your Swap Space

Once you’ve expanded your swap space, keeping track of its usage is essential to ensure your system is running efficiently. The top command in Linux can provide real-time monitoring of your system’s resources, including swap space.


If you notice your system is constantly using a high amount of swap, it may indicate that your system doesn’t have enough physical memory for the tasks at hand. In this case, you might consider adding more RAM or optimizing your applications to use less memory.


Increasing swap space effectively enhances your Linux system’s ability to handle more processes and perform more efficiently, especially when dealing with memory-intensive tasks. However, it should not be used as a substitute for adequate physical memory.

Remember, swap space operates at a much slower speed compared to RAM. So, while it can help in a pinch, relying on it too much can slow down your system. Always aim to strike a balance between your physical memory and swap space usage.

There’s an old saying in the tech world – “The best solution is always tailored to specific needs.” This couldn’t be more accurate when it comes to managing swap space. Always assess your system’s requirements, monitor usage, and adjust accordingly. This way, your Linux machine will always be ready to handle whatever you throw at it.

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