Possible Duplicate:

What is taking up so much space on my disk, beside the filesystem?

I asked this on stackoverflow, but maybe here is a better place.

On my ubuntu 11.10, /dev/sda3 (150GB) is mounted on / and /dev/sda1 (80GB) is mounted on /home. My entire disk has 250GB and the system is reporting I am running out of disk space. Here is the output of df -h:

Filesystem            Size  Used Avail Use% Mounted on

/dev/sda3             149G  141G     0 100% /

udev                  3.9G  4.0K  3.9G   1% /dev

tmpfs                 1.6G  860K  1.6G   1% /run

none                  5.0M     0  5.0M   0% /run/lock

none                  3.9G  508K  3.9G   1% /run/shm

/dev/sda1              74G   15G   56G  21% /home

Ubuntu disk usage analyzer report the same thing. But this is weird because I believe I never used that much space on /. I also check every individual directory under / ( exclude /home ), and they don't use that much space:

8.8M    bin

4.0K    dev

0   initrd.img

0   initrd.img.old

828M    lib

15M lib32

4.0K    lib64

4.0K    media

0   proc

9.2M    sbin

0   sys

1.1G    var

108M    boot

18M etc

4.0K    mnt

40K root

4.0K    selinux

72K tmp

0   vmlinuz

0   vmlinuz.old

16K lost+found

133M    opt

1004K   run

4.0K    srv

5.9G    usr      

Any one could give me some idea what is using up the space? Thanks in advance.

one thing to add is that I turned the ufw log to full, then I noticed some extreme large log files. But I deleted the log files and turned the ufw log to low again. not sure if that's the problem.