Master Linux Disk Usage: Using df and du Commands Effectively

df command

Check disk space usage (cannot view size of a specific directory).

Command format:

df [option]

-h

human‑readable output (e.g., 10K, 10M, 10G) -k display sizes in kilobytes -m display sizes in megabytes -a list all filesystems, including those with size 0 -i show inode information -T display filesystem type

View system partition usage and filesystem type:

df -hT

This command shows each partition’s total, used, and available space.

Check the disk usage of the partition containing a specific directory:

df -h nodedemo/

Display inode information of filesystems:

df -ih

du command

Show the disk space occupied by files or directories.

Command format:

du [option] file/dir

-h

human‑readable output (e.g., 10K, 10M, 10G) -s display only the total size of each argument (default unit kB)

Display the size of the current directory:

du -hs

Show the size of a specific directory or file:

du -hs nodedemo/
du -hs nodedemo/Dockerfile

Display the size of all files in the current directory:

du -hs ./*

Note the difference between du -hs xxxx (shows total size of the directory) and du -hs xxxx/* (lists size of each item inside).

Warning: Running du without options will recursively list every file, producing overwhelming output.