How to Create or Change a Swap File on Debian 13

To create or change a swap file on Debian 13, follow the steps below:

Step 1 : Check whether swap is already enabled:

free -m

Although it is technically possible to use both a swap partition and a swap file, it is not common. This guide assumes your system does not currently have swap configured.

Step 2 : Make sure you have enough free disk space:

df -h

Step 3 : Create a 2 GB swap file:

sudo fallocate -l 2G /swapfile

Step 4 : Restrict access to the swap file for security reasons:

sudo chmod 600 /swapfile

Step 5 : Format the file as swap:

sudo mkswap /swapfile

Step 6 : Activate the swap file:

sudo swapon /swapfile

Step 7 : Confirm that the swap file is enabled:

sudo swapon --show

Step 8 : Edit /etc/fstab to enable the swap file at boot:

sudo nano /etc/fstab

Add the following line:

/swapfile none swap sw 0 0

Save and exit the file.

Step 9 : If you want to change the swap size later, first disable swap:

sudo swapoff /swapfile

Then delete the swap file and repeat the steps above with the new size.

Congratulations, you have successfully created or changed a swap file on Debian 13.