Enable Swap on Ubuntu

Create a swap file on Ubuntu to increase system performance by allowing the system to use disk space as virtual memory.

Create a 2GB swap file:

sudo fallocate -l 2G /swapfile

If fallocate is not available, you can use dd:

sudo dd if=/dev/zero of=/swapfile bs=1G count=2

Set the correct permissions for the swap file:

sudo chmod 600 /swapfile

Make the file a swap file:

sudo mkswap /swapfile

Enable the swap file:

sudo swapon /swapfile

To make the swap file permanent, add it to /etc/fstab:

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

To verify that the swap file is active, you can use:

swapon --show

To check the total swap space available, you can use:

free -h

Swap File Tuning (Optional)

To adjust the swappiness value (optional), which controls how often the system uses swap space, you can edit /etc/sysctl.conf:

sudo nano /etc/sysctl.conf

Add or modify the following line:

vm.swappiness=10

Then apply the changes:

sudo sysctl -p

Note: The default value is usually 60, and setting it to a lower value (like 10) reduces the tendency to use swap space.

sudo swapoff /swapfile

sudo rm /swapfile

This guide provides a simple way to enable and manage swap files on Ubuntu systems.
Adjust the size of the swap file and swappiness value according to your system's needs.
Always ensure you have sufficient disk space before creating a swap file.
This can help improve system performance, especially on systems with limited RAM.
Remember to monitor your system's performance and adjust the swap settings as necessary.
For more advanced configurations, consider using a swap partition instead of a swap file.
This guide is applicable to most Ubuntu versions, including Ubuntu Server and Desktop editions.
Always back up important data before making changes to system configurations.
For more information, refer to the official Ubuntu documentation on swap files.