It is not. Code: ~ $ readlink -f /var/cache/apt/ /opt/var/cache/apt Your advice is useless.
~ $ readlink -f /var/cache/apt/ /opt/var/cache/apt
N900:~# ls -l /var/cache/apt lrwxrwxrwx 1 root root 18 May 25 2010 /var/cache/apt -> /opt/var/cache/apt