61 GB root patition full?

Question

I have a 61 GB root partition for Ubuntu 19.04 that is full. Looking at it with Baobab the devices & location panel says: 1.5GB available 61.5 GB Total Clicking on it, Baobab shows the circle with only 15.2GB used.

1. Why this discrepancy between the two numbers?
2. How could the root be so large? (I clean and autoremove it)
3. Is there a way to compress it?

df -h Filesystem Size Used Avail Use% Mounted on udev 7.7G 0 7.7G 0% /dev tmpfs 1.6G 2.2M 1.6G 1% /run /dev/nvme0n1p3 58G 56G 447M 100% / tmpfs 7.8G 335M 7.4G 5% /dev/shm tmpfs 5.0M 4.0K 5.0M 1% /run/lock tmpfs 7.8G 0 7.8G 0% /sys/fs/cgroup /dev/loop1 142M 142M 0 100% /snap/skype/60 /dev/loop2 89M 89M 0 100% /snap/core/6964 /dev/loop3 90M 90M 0 100% /snap/core/6673 /dev/loop4 148M 148M 0 100% /snap/skype/66 /dev/loop5 54M 54M 0 100% /snap/core18/970 /dev/loop6 212M 212M 0 100% /snap/firefox/226 /dev/loop7 152M 152M 0 100% /snap/gnome-3-28-1804/51 /dev/loop8 175M 175M 0 100% /snap/spotify/32 /dev/loop10 125M 125M 0 100% /snap/code/8 /dev/loop0 174M 174M 0 100% /snap/spotify/34 /dev/loop12 54M 54M 0 100% /snap/core18/782 /dev/loop11 90M 90M 0 100% /snap/core/6818 /dev/loop13 145M 145M 0 100% /snap/skype/63 /dev/loop15 54M 54M 0 100% /snap/core18/941 /dev/loop14 212M 212M 0 100% /snap/firefox/216 /dev/loop16 35M 35M 0 100% /snap/gtk-common-themes/818 /dev/loop19 181M 181M 0 100% /snap/spotify/35 /dev/loop20 8.2M 8.2M 0 100% /snap/evince/68 /dev/loop22 125M 125M 0 100% /snap/code/9 /dev/loop21 36M 36M 0 100% /snap/gtk-common-themes/1198 /dev/loop23 88M 88M 0 100% /snap/meshlab-mardy/5 /dev/loop24 35M 35M 0 100% /snap/gtk-common-themes/1122 /dev/nvme0n1p2 511M 7.7M 504M 2% /boot/efi /dev/nvme0n1p4 412G 155G 257G 38% /home tmpfs 1.6G 76K 1.6G 1% /run/user/1000 /dev/loop25 8.2M 8.2M 0 100% /snap/evince/95 /dev/loop26 152M 152M 0 100% /snap/gnome-3-28-1804/55

sudo du -hx --max-depth=1 / 2> /dev/null 66M /boot 17M /etc 0 /media 4.6G /var 17M /bin 805M /lib 4.0K /lib64 0 /mnt 1.9G /opt 39M /root 12M /sbin 80K /snap 0 /srv 29M /tmp 7.1G /usr 0 /cdrom 0 /.config 15G /

sudo du -sh /root/.[A-z]* /root/* du: cannot access '/root/.[A-z]': No such file or directory du: cannot access '/root/': No such file or directory

Just copying the end of a very long list here: sudo du -ckmax / | sort -nk 1,1 | tee ~/output 137 /usr/local/lib/python2.7/dist-packages 141 /var/lib/snapd/cache/ea230569aca785460ef3c852ba6991a714794797d20db58b83e82c2d9ea7adad43eaeae93269a39302c69c81cd0c5c6e 142 /var/lib/snapd/snaps/skype_60.snap 143 /usr/lib/jvm/java-11-openjdk-amd64/jmods/java.base.jmod 143 /var/cache 145 /var/lib/snapd/snaps/skype_63.snap 148 /var/lib/snapd/snaps/skype_66.snap 151 /usr/share/texlive/texmf-dist/tex 152 /var/lib/snapd/snaps/gnome-3-28-1804_51.snap 152 /var/lib/snapd/snaps/gnome-3-28-1804_55.snap 154 /usr/lib/gcc 154 /usr/lib/gcc/x86_64-linux-gnu 155 /usr/lib/python2.7 157 /usr/lib/thunderbird 157 /usr/local 162 /usr/lib/chromium-browser/chromium-browser 167 /lib/modules/5.0.0-15-generic/kernel/drivers 174 /var/lib/snapd/snaps/spotify_34.snap 175 /var/lib/snapd/snaps/spotify_32.snap 178 /usr/lib/jvm/java-11-openjdk-amd64/lib 178 /var/lib/apt 178 /var/lib/apt/lists 181 /var/lib/snapd/snaps/spotify_35.snap 193 /usr/share/locale 200 /usr/share/doc/texlive-doc 205 /opt/libreoffice6.0/share 206 /usr/lib/i386-linux-gnu/wine 207 /usr/lib/jvm/java-11-openjdk-amd64/jmods 207 /usr/share/fonts 212 /var/lib/snapd/snaps/firefox_216.snap 212 /var/lib/snapd/snaps/firefox_226.snap 219 /usr/lib/x86_64-linux-gnu/wine 223 /usr/lib/chromium-browser 232 /lib/modules/5.0.0-15-generic/kernel 235 /opt/libreoffice6.2/share 238 /lib/modules/5.0.0-15-generic 261 /opt/mendeleydesktop/lib/qt 264 /usr/share/icons 284 /opt/mendeleydesktop/lib 286 /usr/share/texlive/texmf-dist 288 /usr/share/texlive 318 /lib/modules 350 /opt/mendeleydesktop 357 /opt/libreoffice6.0/program 363 /opt/libreoffice6.2/program 386 /usr/lib/jvm 386 /usr/lib/jvm/java-11-openjdk-amd64 406 /usr/bin 406 /usr/lib/i386-linux-gnu 411 /usr/share/doc 430 /lib/firmware 554 /var/lib/snapd/cache 566 /opt/libreoffice6.0 621 /opt/libreoffice6.2 667 /usr/share/tesseract-ocr 667 /usr/share/tesseract-ocr/4.00 667 /usr/share/tesseract-ocr/4.00/tessdata 800 /var/log/journal 800 /var/log/journal/8c65d4da432b4013bf2f5e080b2544f4 805 /lib 844 /var/log 1575 /usr/lib/x86_64-linux-gnu 1887 /opt 2572 /var/lib/snapd/snaps 2947 /usr/share 3128 /var/lib/snapd 3498 /var/lib 3510 /usr/lib 4612 /var 7187 /usr 14667 / 14667 total

Answer 1

Try sudo du -ckmax / | sort -nk 1,1 | tee ~/output to figure out what's taking up the space.

Alternatively, you might have some open file handles to deleted files taking up a bunch of space. Try running this to see if anything large is hidden:

sudo lsof | grep -i deleted

If there some large deleted files with open file handles, kill the process with the file handle to free the space. You can also just reboot to clear it also.