I don't get where my linux space is gone.
when i run df -h, it shows used 15 GB of total 20 GB
when I run ncdu program, to find what takes, I do sudo ncdu in my root directory. And I see sorted by size directories:
1.3 GB usr
and later is 19 MB lib and so on
so adding up - the space is 4.7+4.5+1.3 = 10.5. OK plus those small directoreis lets roudn to 11 GB used. So where are my 4 GB then?