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:

<code>df -hT</code>

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

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

<code>df -h nodedemo/</code>

Display inode information of filesystems:

<code>df -ih</code>

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:

<code>du -hs</code>

Show the size of a specific directory or file:

<code>du -hs nodedemo/
du -hs nodedemo/Dockerfile</code>

Display the size of all files in the current directory:

<code>du -hs ./*</code>

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.