The first step in investigating a disk usage issue is to find where the content is being used. This will allow you to remove unnecessary content (such as old backups) and make changes to prevent the issue from happening again. For full WHM/cPanel documentation, see https://docs.cpanel.net

Warning: If you don't know the purpose of a file or folder, don't remove it. Removing system files or directories is irreversible and may break the server (taking all of the sites down).

For an overview of your disk usage, select Server Information from the Server Status section on the left. Scroll to the bottom of the screen to see the server's disk usage.

To find the disk usage by domain, go to the Account Information section and select List Accounts.

Note: If quotas are properly enabled on your server, you should see the disk used by each cPanel account in the Disk Used column. Select the cP icon to launch into any cPanel account with a large amount of disk usage. If quotas aren't enabled (on our generation 3 servers for example), disk usage won't be reported correctly in this view and you should check each account separately.

From cPanel, select the Disk Usage icon in the Files subsection.

Scroll to the bottom of the screen and select the radio button to sort by disk usage.

From here, the largest directories will be visible at the top of the list.

Select the caret next to any directory to expand and you'll see the sizes of any subdirectories.

Select the carets next to any subdirectory to drill down further.

Select on the name of any directory to open it in the file manager.

For site specific usage, you can remove it from the File Manager.

Go back to the main cPanel page for the domain.

Select File Manager in the Files section. Be sure to select View Trash and Empty Trash to permanently delete the files.

Next steps:

Disk space issues can also be caused by inodes. After reviewing your disk space usage, move on to find inode usage. It's important to identify and correct the root issue that caused the disk space to become exhausted. Move on to preventing disk usage issues.