Why is my rootfs filling up so fast?

Question

I'm trying out Linux by installing openSUSE 12.2 x64 on VirtualBox; the host is 64 bit Windows 7 Ultimate. I gave the install 16GB of storage - I will only be messing around with it - I thought this should be plenty. By default, Virtual Box splits the storage you give it roughly in half - giving half to the rootfs and about half to user space.

I've figured out via previous attempts that when the rootfs partition gets full - nothing works. But I've hardly done anything with it - I've installed Linux, run some updates and haven't even installed any extra software. I'm seeing that my rootfs is filling up fast - 83% already with no extra software installed - and hardly anything is going to my other partition (/home).

Is this expected behavior? Does all installed software get installed to the rootfs? I've heard you should try to keep rootfs as small as possible, but all I've done is install Linux and update the system and it's at 4.8 GB - 83% full.

How can I keep my rootfs from filling up? Should I have adjusted the VirtualBox defaults to just make rootfs bigger?

Here's the results from a df: Notice how the /dev/sda3 is hardly used.

linux-5guy:/ # df -h                                                                                 
Filesystem      Size  Used Avail Use% Mounted on                                                        
rootfs          6.1G  5.1G  732M  88% /                                                                 
devtmpfs        2.0G   36K  2.0G   1% /dev
tmpfs           2.0G   80K  2.0G   1% /dev/shm
tmpfs           2.0G  552K  2.0G   1% /run
/dev/sda2       6.1G  5.1G  732M  88% /
tmpfs           2.0G     0  2.0G   0% /sys/fs/cgroup
tmpfs           2.0G     0  2.0G   0% /media
tmpfs           2.0G  552K  2.0G   1% /var/lock
tmpfs           2.0G  552K  2.0G   1% /var/run
/dev/sda3       7.8G  410M  7.0G   6% /home

Answer 1

sudo su
cd /
du -mx . | sort -n -r > directorySizesInMegabytes

Check the contents of directorySizesInMegabytes to find culprit.

du = disk usage -m = show sizes in mbs -x = skip directories on different file systems

^^ This gives dir sizes in the first column.

sort -n = numeric sort -r = reverse order i.e. largest-to-smallest

Answer 2

Try install baobab here,

Launch it with gksudo baobab / or gksu baobab /,

It will give you a very much detailed disk usage, so you would know which part(folder) it taking most of spaces.

Answer 3

It could be that it is the cache of the package manage that fills up the rootfs. That what happens to me all the time. For zypper it should be located under /var/cache/zypper/RPMS. You should be able to clean the cache by running zypper clean.

I don't use OpenSuse so I'm not sure about this because from a quick google there seems to be some dispute about zypper having a cache...