Debian Hint #31: Disabling a normally-active service in a specific runlevel should be done by changing the S link in /etc/rc.d to a K link, rather than removing the link entirely; if all links are removed, the system will assume on the next install that they need to be replaced.

Debian Hint #31: Disabling a normally-active service in a specific runlevel should be done by changing the S link in /etc/rc<level>.d to a K link, rather than removing the link entirely; if all links are removed, the system will assume on the next install that they need to be replaced.