****@localhost:~$ apt-get clean
E: Could not open lock file /var/cache/apt/archives/lock - open (13: Permission denied)
E: Unable to lock the download directory
****@localhost:~$ sudo apt-get clean
****@localhost:~$ df -h
Filesystem             Size  Used Avail Use% Mounted on
/dev/mapper/vg00-root  9.4G  9.2G     0 100% /
udev                   7.9G  4.0K  7.9G   1% /dev
tmpfs                  1.6G  364K  1.6G   1% /run
none                   5.0M     0  5.0M   0% /run/lock
none                   7.9G   12K  7.9G   1% /run/shm
/dev/mapper/vg00-tmp   3.8G  117M  3.5G   4% /tmp
/dev/md0               462M   28M  411M   7% /boot
/dev/mapper/vg00-home   11T  7.7T  2.7T  75% /home