How To Configure Virtual Memory (Swap File) on Ubuntu 24.04

Are you running out of RAM on your Ubuntu 24.04 system? Or perhaps you want to improve system stability during heavy workloads? Configuring a swap file can help extend your system’s virtual memory, providing a buffer when physical RAM is fully utilized. In this guide, we’ll walk you through the steps to set up and optimize swap space on Ubuntu 24.04.

Why Use Swap Space?

Swap acts as an overflow area on your storage device, allowing the OS to move inactive pages from RAM to disk. While it’s slower than physical memory, it can prevent system crashes and improve performance under high load.

Step 1: Check Existing Swap Space

Before creating a new swap file, verify if you already have one:

swapon --show

If no output appears, it means there’s no active swap.

Step 2: Create a Swap File

1. Choose the size of your swap file.
   For example, to create a 4GB swap file:

sudo fallocate -l 4G /swapfile

Note: If fallocate isn’t available or causes issues, you can use dd:

sudo dd if=/dev/zero of=/swapfile bs=1G count=4 status=progress

2. Set the correct permissions:

sudo chmod 600 /swapfile

Step 3: Set Up the Swap Area

Format the file as swap:

sudo mkswap /swapfile

Step 4: Enable the Swap File

Activate the swap:

sudo swapon /swapfile

To verify it’s active:

swapon --show

Step 5: Make the Swap Permanent

To ensure the swap file persists after reboot, add it to /etc/fstab:

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

Step 6: Optimize Swap Settings (Optional)

Adjust the swappiness parameter to control how aggressively your system uses swap. A lower value favors RAM usage; a higher value uses swap more readily.

Check current swappiness:

cat /proc/sys/vm/swappiness

Set swappiness to, for example, 10 (more RAM preference):

sudo sysctl vm.swappiness=10

To make this change persistent across reboots, add to /etc/sysctl.conf:

echo 'vm.swappiness=10' | sudo tee -a /etc/sysctl.conf

Final Tips

• Monitoring Swap Usage: Use free -h or htop to monitor swap activity.
• Avoid Over-allocating Swap: Keep swap size reasonable; excessive swap can degrade performance.
• Consider SSDs: If you’re using an SSD, swap can be faster, but be mindful of wear over time.

Conclusion

Configuring swap space on Ubuntu 24.04 is straightforward and can significantly improve system stability under heavy workloads. Whether you’re running a server or a desktop, having an appropriately sized swap file ensures your system remains responsive and resilient.

If you have questions or need further assistance, feel free to reach out to our support team at Greenhost.cloud!

Stay tuned for more tips on optimizing your Ubuntu systems and cloud infrastructure.