I was getting the following error on one my servers, after updating apache2 and php5
Starting web server (apache2)...(98)Address already in use: make_sock: could not bind to address [::]:80 (98)Address already in use: make_sock: could not bind to address 0.0.0.0:80 no listening sockets available, shutting down Unable to open logs failed!
This is what I did to fix the problem
netstat -lnp | grep '80'#output tcp6 0 0 :::80 :::* LISTEN 18712/apache2
In my case the output showed that apache2 was already using the port, although no sites was working and it was not even possible to stop the apache2 daemon. I ran the following to learn more
ps 18712 PID TTY STAT TIME COMMAND 18712 ? Ss 0:00 /usr/sbin/apache2 -k start
I killed the apache2 process, which was blocking everything
and restarted apache
and everything was working fine again. Hopefully this is useful for someone..