Use the Linux df command to show free disk space

By Alvin Alexander. Last updated: June 4, 2016

Linux free disk space FAQ: How do I show free disk space on a Unix or Linux system?

The Linux df command stands for "disk free". It is meant to show Linux disk space information, including disk space that is used, disk space remaining, and how filesystems are mounted on your Linux (or Unix) system. The Linux df command not only shows the free disk space on your local computer, it also shows the free disk space on all networked filesystems that are mounted by your Linux system.

A Linux df command example

Here's the most basic example of Linux df command, with output shown here from a CentOS Linux computer:

$ df

Filesystem  1K-blocks   Used     Available  Use%  Mounted on
/dev/vzfs   10485760    5713424  4772336    55%   /

Rather than try to explain that particular output, let me say that I never use the df command that way any more. Instead, I always use the -h option to the df command, like this:

$ df -h

Filesystem   Size  Used  Avail  Use%  Mounted on
/dev/vzfs    10G   5.5G  4.6G   55%   /

The -h option stands for "human readable", so as you can see, my current Linux system has one filesystem, and it is mounted as / (the root filesystem), and it is a 10GB filesystem, with 5.5GB used, 4.6GB available, and it is 55% used (which is pretty easy to see with round numbers like this example).

A Mac OS X (Unix) df command example with many filesystems

While my current Linux system has only one filesystem, which is mounted as the root directory (/), my Mac OS X 10.5.x system (which is a Unix-based operating system) has several filesystems, and I can also see its "disk free" information with the Unix df command:

$ df -h

Filesystem      Size   Used  Avail Capacity  Mounted on
/dev/disk0s2    93Gi   82Gi   11Gi    89%    /
devfs          107Ki  107Ki    0Bi   100%    /dev
map -hosts       0Bi    0Bi    0Bi   100%    /net
map auto_home    0Bi    0Bi    0Bi   100%    /home

As you can see, this Mac has four filesystems that are mounted on /, /dev, /net, and /home. You can also see that the format of this output is a little different than the format from my CentOS Linux system. (And most importantly for me, you can see that my primary 93GB filesystem is 89% full -- yikes, I have to go!)

More Linux df command information

If you have Linux or Unix df command examples you'd like to share, including output from other systems, feel free to share that output in the comments section below. As usual, you can also look at your Linux/Unix man page on the df command to get more help, like this: