/ is full. How do I find out what's taking up space?

Question

I Recently noticed an lightweight app (Sonarr) wasn't running, so when into webmin to find a fidk fill error. '/' was 100% full. I have hunted around and sound a few commands to get a bit of short term space back (down to 96%), but there shouldn't be that much usage. I'm just running Ubuntu Server LTS18 and a couple of apps on a 120GB SSD. But I am seeing the below and cannot (and do no know how to) find where the heavy directories and/or file are in /.

Filesystem                                 Size  Used Avail Use% Mounted on
udev                                       7.3G     0  7.3G   0% /dev
tmpfs                                      1.5G  2.8M  1.5G   1% /run
/dev/sde2                                  110G  104G  4.6G  96% /
tmpfs                                      7.3G   12K  7.3G   1% /dev/shm
tmpfs                                      5.0M     0  5.0M   0% /run/lock
tmpfs                                      7.3G     0  7.3G   0% /sys/fs/cgroup
/dev/loop0                                  90M   90M     0 100% /snap/core/7917
/dev/loop1                                  90M   90M     0 100% /snap/core/8039

Related: No more disk space: How can I find what is taking up the space? — steeldriver, Nov 23 '19 at 13:14
Type sudo du /* -sch. You will see which directory takes too much space. Then you can dig into that directory sudo du /directory/*, to see what takes space there. And so on until you find what is your problem. — nobody, Nov 23 '19 at 14:11

score 4 · Accepted Answer · answered Nov 23 '19 at 15:12

4

Try to install ncdu - it is a graphical disk usage app for the command line.

sudo apt-get install ncdu

And then

ncdu /

Then you'll see a list of the directories within / - you can navigate the directories and drill into them by hitting enter.

answered Nov 23 '19 at 15:12

Jürgen Gmach

695
5
12

to free up some space you can always try: sudo apt-get -y autoremove && sudo apt-get -y clean – AlexOnLinux Nov 23 '19 at 16:08
That solved my problem after I used @WinEunuuchs2Unix solution to narrow down the field (running ncdu on / is was going on for hours so had to quite it) to my /var directory. Turns out plex is the culprit - it's hording metadata) Thanks team! – wobbler Nov 24 '19 at 09:59

score 2 · Answer 2 · answered Nov 23 '19 at 17:03

The other answer recommends installing ncdu which appears to be a great tool and loved by many users. However this is a "Catch 22" situation because when you are out of disk space you usually can't install a program to find out why because... you have no disk space.

The only option is to use a program already installed:

$ sudo du -cha --max-depth=1 --exclude=/mnt / 2>/dev/null

40M     /core
1.7G    /var
6.5M    /dev
15M     /bin
3.4M    /tmp
681M    /opt
6.5G    /usr
4.4G    /lib
3.9M    /lib32
17M     /root
15M     /etc
1.1G    /boot
12G     /home
13M     /sbin
1.8M    /run
26G     /
26G     total

In this case there is no catch 22, as you can see in the question, that there are 4.6G free space on disk. — Jürgen Gmach, Nov 23 '19 at 20:10

/ is full. How do I find out what's taking up space?

2 Answers2