I'm really having a hard time to process these results on my Ubuntu server. I have a major problem with my JBoss server where I get FileNotFoundExceptions along with "No space left on device" errors. And I thought "maybe I'm out of disk space", and used df command to figure out how much I have left:

root@ubuntu1:/# df -h
Filsystem            Storlek Anvnt Tillg Anv% Monterat på
/dev/mapper/ubuntu1-root
                       36G   13G   21G  38% /
none                  2,0G  192K  2,0G   1% /dev
none                  2,0G     0  2,0G   0% /dev/shm
none                  2,0G   64K  2,0G   1% /var/run
none                  2,0G     0  2,0G   0% /var/lock
/dev/sda1             228M   23M  193M  11% /boot
/dev/mapper/vgdata-lvdata
                       79G  9,2G   66G  13% /data

And as you can see, I have plenty of space left. And I also checked if I'm out of i-nodes:

root@ubuntu1:/# df -i
Filsystem            Inoder    IAnv   IFria IAnv% Monterat på
/dev/mapper/ubuntu1-root
                     2346512   61992 2284520    3% /
none                  505380     773  504607    1% /dev
none                  507383       1  507382    1% /dev/shm
none                  507383      30  507353    1% /var/run
none                  507383       2  507381    1% /var/lock
/dev/sda1             124496     230  124266    1% /boot
/dev/mapper/vgdata-lvdata
                     10486784  233945 10252839    3% /data

But then i used du:

root@ubuntu1:/# du -s -h /*
7,5M    /bin
23M     /boot
19G     /data
192K    /dev
11G     /eniro
5,3M    /etc
112K    /home
0       /initrd.img
183M    /lib
0       /lib64
16K     /lost+found
12K     /media
4,0K    /mnt
4,0K    /opt
du: kan inte komma åt "/proc/20452/task/20452/fd/3": Filen eller katalogen finns inte
du: kan inte komma åt "/proc/20452/task/20452/fdinfo/3": Filen eller katalogen finns inte
du: kan inte komma åt "/proc/20452/fd/3": Filen eller katalogen finns inte
du: kan inte komma åt "/proc/20452/fdinfo/3": Filen eller katalogen finns inte
0       /proc
18M     /root
8,2M    /sbin
4,0K    /selinux
8,0K    /srv
0       /sys
40K     /tmp
691M    /usr
1,2G    /var
0       /vmlinuz

Notice that /data and /eniro are 30G combined! How is it possible? Do I have a memory leak somewhere? Or is it something else?

----- EDIT 1 -----

Ok, I figured out that /data has its own mount so it's not possible to combine /data and /eniro because they aren't on the same mount. But how come it says 9,2G on the first command when it says 19G on the third on directory /data?