Increase Swap Memory in Ubuntu

Swap memory serves as a backup for your system's RAM, utilizing the hard disk to provide additional space when your RAM is fully utilized. While it is slower than RAM due to the hard disk's lower speed, it is crucial in preventing system crashes by allowing the operating system to offload less frequently used data from memory.
Increasing your swap space can be a simple yet effective solution if you're experiencing slow performance or need to run applications requiring significant memory resources.

Step-by-Step Guide to Increasing Swap Memory

Step 1: Check Current Swap Space
Before making any changes, check your current swap space using:

sudo swapon --show

This command lists all active swap partitions and files. If there's no output, you don't have any swap space configured.

Step 2: Check Available Disk Space
Ensure you have enough free disk space by running:

df -h

This command shows your disk space in a human-readable format.

Step 3: Create a Swap File
Create a swap file with:

sudo fallocate -l 2G /swapfile

This allocates 2 gigabytes for the swap file. Adjust the size as needed.

Step 4: Enable the Swap File
Set the correct permissions:

sudo chmod 600 /swapfile

Format the swap file:

sudo mkswap /swapfile

Enable the swap file immediately:

sudo swapon /swapfile

Verify it's active:

sudo swapon --show

Step 5: Make the Swap File Permanent
Backup your fstab file:

sudo cp /etc/fstab /etc/fstab.bak

Add the swap file to fstab:

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

Step 6: Adjust Swappiness and Cache Pressure

Swappiness controls how often your system uses swap space. A lower value (e.g., 10) means the system prefers RAM over swap, while a higher value (e.g., 100) increases swap usage.

Adjust how often the system uses swap space:

sudo sysctl vm.swappiness=10

Cache pressure affects how the system manages cached files. A lower value (e.g., 50) reduces the frequency of cache regeneration.

Improve cache performance:

sudo sysctl vm.vfs_cache_pressure=50

To make Swappiness and Pressure permanent, add lines below at the bottom of /etc/sysctl.conf:

sudo nano /etc/sysctl.conf

# Add lines given below at bottom of /etc/sysctl.conf
vm.swappiness=10
vm.vfs_cache_pressure=50

Save and close the file.

Step 7: Removing Old Swap Files

sudo swapoff /path/to/old/swapfile

Remove the entry from fstab and delete the file.

Conclusion
Increasing swap memory can significantly improve your system's performance, especially when running memory-intensive applications. Following these steps ensures your system has the resources it needs to run smoothly. Remember to monitor your memory usage and adjust settings as required for optimal performance.