A first shot: High traffic in an error log. I guess if you would download videos, you would know it. :)

 sudo du -sh /var/log

• -s is summary


• -h is human readable (k, M, G, T) suffix

For me it is 20M, and beside the log-directory, there is a cache for the installations. Use

 apt-get clean 

If this is your problem.

Of course, you should check /home if it is in your root partition.

If you have to search big files iteratively, I can suggest a series of commands, which can be repeated and is pretty fast after the first initial step:

• You start at a suspicious directory at top level


• Then you search all subdirs and files for their size, and sort numerically:

sudo du -s /var/* | sort -n 

0   /var/crash

4   /var/www

44  /var/games

124 /var/run

2306    /var/tmp

18538   /var/log

251876  /var/cache

1053231 /var/lib

• I stripped the example, to keep it short. So we see, that the bigest subdir is /var/lib, and repeat the step for /var/lib. Now the search is much faster, because the computated results are somehow cached:

sudo du -s /var/lib/* | sort -n 

78116   /var/lib/apt-xapian-index

104580  /var/lib/dpkg

680503  /var/lib/postgresql

and so on. Follow the biggest dirs to find the bigger files. You can't use -sh here, because sorting numerically does not work with the k/M/G/T for kilobyte and so on.