Первая загадка, капаем по-поверхности: df говорит, что занято 11G, а du 8.8G. Где еще 2.2G?
Вторая загадка: смотрим лог du и видим, что используется около 4-4.5G. Куда девались еще 4G?
p.s. ext4, Ubuntu 9.10, amd64.
~ % df
Filesystem Size Used Avail Use% Mounted on
...
/dev/sdb6 12G 11G 271M 98% /home
...~ % du --max-depth=1
1.0M ./.macromedia
1.9M ./.evolution
28K ./.xine
24K ./.icons
4.6M ./.chmsee
564K ./.gstreamer-0.10
48K ./.quodlibet
316K ./.compiz
72M ./Developer
844M ./tmp
2.6M ./.gconf
40K ./.pki
60K ./.python-eggs
75M ./.cache
56M ./.config
216K ./.opera_widget_installer
136K ./.saves
5.1M ./.fonts
21M ./.wine
12K ./.gnome
444K ./.gnome2
42M ./.opera
4.0K ./.nautilus
12M ./.local
2.0M ./.openoffice.org
150M ./.mozilla-orig
1.7G ./Applications
4.0K ./.ssh
148K ./.pulse
552K ./.softmaker
24K ./.vim
12K ./.fltk
24K ./.easytag
16K ./.dbus
12K ./.eclipse
16K ./.gnochm
4.0K ./.wapi
16K ./.emacs.d
199M ./.mozilla
16K ./.kde
4.0K ./.gnome2_private
36K ./.FBReader
4.0K ./.gpilotd
76K ./.designer
300K ./.java
180K ./.Skype
32K ./.dvdcss
0 ./.gvfs
75M ./.goldendict
80K ./.gdesklets
37M ./.thumbnails
129M ./Documents
4.0K ./.update-notifier
256K ./.themes
28K ./.VirtualBox
60K ./.xchat2
16K ./.mcop
96K ./.gconfd
16K ./.gegl-0.0
20K ./.gnupg
16K ./.adobe
4.0K ./.icedteaplugin
67M ./Desktop
12K ./.avidemux
2.2M ./.gajim
8.0K ./.qt
164K ./.psi
720K ./.ipython
728K ./.fontconfig
3.8M ./.kde3
8.0K ./.mplayer
16K ./.screenlets
460K ./.gimp-2.6
12K ./.update-manager-core
32K ./.mission-control
8.8G .
