Examining Disk Usage on Linux Systems
An important part of administering any system is making sure you're not at your disk space limit. This is especially true when running something like a media center or NAS which may run nightly download or backup jobs.
The GUI Way
Most linux distributions' file browsing app will also display
free vs. used disk space in a bottom or top bar. Alternatively
you can always navigate to / and right-click somewhere to open
a properties window. Chances are you'll find what you're looking for.
The Terminal Way
In other cases it may be advantageous to examing disk usage
from the command line. The most common use case is during an ssh
session where a GUI option isn't viable. To examine disk usage
in the terminal, do the following:
Check Overall Disk Usage
$ df -h
Filesystem Size Used Avail Use% Mounted on
udev 1.9G 0 1.9G 0% /dev
tmpfs 390M 1.5M 388M 1% /run
/dev/disk1 28G 5G 21G 23% /dev/disk1
Finding Large Files & Folders
As disk usage creeps up you may find yourself wanting
to perfom an audit of your system. In doing so, you
may be able to find & delete big files/folders that
are no longer needed. To do this, I recommend ncdu.
ncdu is an ncurses utility that builds a filetree
of your system directories and lets you browse them
in the terminal. Folders are sorted from the supplied
path by their size, which makes it easy to see what's
taking up space on your disk.
Installing NCDU
sudo apt install ncdu
and yer done.
Using NCDU
ncdu <optional-filepath>
If no filepath is supplied, ncdu will build a listing based on the current working directory. It's really that simple!