can't log in even with live cd

[amged]

i'm using ubuntu 12.04 and try to copy Files to video directory.
there was no enough memory space so i used `sudo nautails` to `copy them any way` as a root.
last time i checked -before shutdown- home has 0 mb free but 7gb available.
now i can't log in. i tried to use a live cd and mount the home directory as a root but failed.

[rokytnji]

i tried to use a live cd

What does

df -h

show for /home running live cd?

Mine in Ubuntu 10.04 for reference

Filesystem            Size  Used Avail Use% Mounted on
/dev/sda5             7.1G  3.0G  3.8G  44% /
none                  490M  252K  490M   1% /dev
none                  495M  648K  494M   1% /dev/shm
none                  495M   96K  494M   1% /var/run
none                  495M     0  495M   0% /var/lock
none                  495M     0  495M   0% /lib/init/rw
/dev/sda6              25G  2.9G   21G  13% /home