The du command is the quick way to check how much disk space a directory is using on Linux or Unix systems.
Check the size of a directory
du -sh /path/to/directory
Example:
du -sh /var/www/
Example output:
1.5G /var/www/
Options used
-s: show only the total size for the directory.-h: show the result in a human-readable format such as KB, MB or GB.
This is useful when checking log directories, web roots, backup folders or any path that may be consuming unexpected disk space.