Forum OpenACS Q&A: how to use AOLServer and Apache on same machine at different ports

I am using a Ubuntu virtual machine.Where I installed OpenACS .To do so I had first shutdown Apache on this machine service apache2 stop

and then as per instructions given here

https://openacs.org/xowiki/ubuntu

Step 1)
aptitude install postgresql

Step 2)
aptitude install openacs

I had to shutdown Apache to do above installation.
Now the installation finishes.So I can access http://localhost:8000

but when ever I try to start Apache on this machine which was shutdown during installation I see the error


service apache2 start
* Starting web server apache2 (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

So I thought may be OpenACS installs AOLServer so Aolserver might be listening on port 80 I check

/etc/aolserver4/conf.d/openacs.sh

and here

AOL_USER=www-data
AOL_GROUP=www-data
AOL_ADDRESS=192.168.1.15
AOL_PORT=8000
RUN_DAEMON=yes

So AOLServer is not listening on port 80 upto here it is confirmed.

netstat -tualp | grep 80
tcp 0 0 somemachine.somedimain.:8000 *:* LISTEN 21321/aolserver4-ns

so netstat shows only 8000 in use.
Then why am I unable to start Apache in this case?

Thanks for helping out Hector.
That is is some useful information.I was able to get back apache running also.

Before I made changes as you mentioned
Here are the entries of /etc/default/aolserver4 file

# These variables can be customized to change main AOLserver settings.
# More changes can be done by modifying the /etc/aolserver4/aolserver4.tcl Tcl script.
#
# Note that these variables are read and interpreted by the Tcl script
# too, so avoid using shell capabilities in setting vars.
#

#USER=www-data
#GROUP=www-data
#HOSTNAME=localhost
#ADDRESS=127.0.0.1
#HTTP_PORT=80
#HTTPS_PORT=443
#CONF=/etc/aolserver4/aolserver4.tcl
#RUN_DAEMON=yes

Which after your suggestion I changed to
RUN_DAEMON=no and then restarted aolserver and started Apache2

/etc/init.d/aolserver4 restart
/etc/init.d/apache2 start

Now I am able to use both AOLserver and Apache2 at the same machine.