How To Free Linux Memory

As you use your Linux system, it’s entirely possible to encounter a situation where the system runs low on memory. Thankfully, the Linux operating system provides several ways to manage and free up memory. If you’re new to Linux and want to learn how to free up memory, this blog post is tailored for you.

1. Free Command

The ‘free’ command is the most straightforward method to check your Linux system’s memory usage. It displays the total amount of free and used physical and swap memory in the system.

To use the free command, simply open your terminal and type:

free -h

In this command, the -h flag stands for ‘human-readable’, which presents information in a format that’s easier to understand.

2. Dropping Cache

Another way to free up Linux memory is to clear the system cache. While Linux uses disk caching to speed up your system, it might take up considerable memory. Luckily, Linux offers an option to clean up cache without disrupting any processes or services.

To clear all PageCache, dentries and inodes, use the command:

echo 3 > /proc/sys/vm/drop_caches

It’s important to note that you should only do this when there is a critical need to free up system memory. Frequent cache clearing might end up slowing down your system.

3. Swap Space

Swap is a space on your hard drive that has been designated as a place where the operating system can store data from the RAM, so that it can free up memory for active processes. If your system is running low on physical memory, managing swap space can be a lifesaver.

To see the swap space, use the command:

swapon -s

To increase the swap space, you can use the fallocate command. For example, to increase it by 1GB, use:

fallocate -l 1G /swapfile


Managing memory is an integral part of maintaining a healthy and responsive Linux system. By using the ‘free’ command, cleaning cache, and properly managing swap space, you can ensure that your system runs efficiently even when under heavy loads.

Remember, freeing up memory is a task that should be done carefully to avoid disrupting system performance. Always make sure to monitor your system’s memory usage before taking any drastic measures. Happy Linuxing!