How to Find Largest Directories in Linux

When working with Linux systems, it’s common to come across directories that are taking up a lot of space on your hard drive. This can be a problem if you’re running low on disk space, or if you want to clean up your system and remove unnecessary files. In this article, we’ll show you how to use the find command to locate the largest directories on your Linux system.

What is the find command?

find is a powerful command-line tool that allows you to search for files and directories based on various criteria, such as name, type, size, and more. The find command is available on most Unix-based systems, including Linux.

The basic syntax of the find command is as follows:

find [path] [expression]

Here, [path] specifies the starting directory for the search, and [expression] specifies the search criteria. The find command will search for all files and directories that match the criteria and print their names to the console.

How to Find the Largest Directories in Linux

To find the largest directories on your Linux system, you can use the du command to calculate the disk usage of each directory, and then pipe the output to the sort command to sort the results by size. Finally, you can use the head command to display the top N directories.

Here’s the basic command to find the top 10 largest directories on your Linux system:

du -h / | sort -hr | head -n 10

Let’s break down the command:

• du -h / calculates the disk usage of all directories under the root directory (/), and prints the results in human-readable format (-h).
• sort -hr sorts the output of du in reverse order (-r) based on the size of each directory (-h).
• head -n 10 displays the top 10 largest directories.

You can adjust the number of directories displayed by changing the value of n in the head command.

Understanding the Output

When you run the du command, it will print the disk usage of each directory in bytes. When you pipe the output to the sort command, it will convert the sizes to a more human-readable format (e.g. 1K, 1M, 1G) and sort the results based on the size.

Here’s an example output of the du command:

1234567 /var/log
987654 /usr/share

This means that the /var/log directory is using 1234567 bytes (or approximately 1.2 MB) of disk space, and the /usr/share directory is using 987654 bytes (or approximately 0.9 MB) of disk space.

Filtering Directories by Size

If you want to find directories that are larger than a certain size, you can use the find command with the -size option. For example, to find all directories under the root directory (/) that are larger than 1 GB, you can run the following command:

find / -type d -size +1G

Let’s break down the command:

• find / searches for all files and directories under the root directory (/).
• -type d specifies that we’re only interested in directories.
• -size +1G specifies that we’re only interested in directories that are larger than 1 GB.

You can adjust the size threshold by changing the value after the + sign. For example, +100M would find directories larger than 100 MB.

Conclusion

In this article, we’ve shown you how to use the find command to locate the largest directories on your Linux system. By using the du, sort, and head commands together, you can quickly find the directories that are taking up the most space on your hard drive. We’ve also shown you how to filter directories by size using the find command. With these tools, you can easily manage your disk space and keep your Linux system running smoothly.