AH00526: Syntax error on line 74 of /etc/apache2/apache2.conf: Invalid Mutex directory in argument file:${APACHE_LOCK_DIR}

Question

I'm new to Apache2, and I'm trying to get Apache2 running on my local Linux (linux mint 17). When I try to: sudo apache2, it gives me following error:

[Mon Jul 20 16:15:30.785526 2015] [core:warn] [pid 14221] AH00111: Config variable ${APACHE_LOCK_DIR} is not defined [Mon Jul 20 16:15:30.785602 2015] [core:warn] [pid 14221] AH00111: Config variable ${APACHE_PID_FILE} is not defined [Mon Jul 20 16:15:30.785618 2015] [core:warn] [pid 14221] AH00111: Config variable ${APACHE_RUN_USER} is not defined [Mon Jul 20 16:15:30.785627 2015] [core:warn] [pid 14221] AH00111: Config variable ${APACHE_RUN_GROUP} is not defined [Mon Jul 20 16:15:30.785644 2015] [core:warn] [pid 14221] AH00111: Config variable ${APACHE_LOG_DIR} is not defined [Mon Jul 20 16:15:30.787550 2015] [core:warn] [pid 14221:tid 140466817042304] AH00111: Config variable ${APACHE_LOG_DIR} is not defined [Mon Jul 20 16:15:30.787686 2015] [core:warn] [pid 14221:tid 140466817042304] AH00111: Config variable ${APACHE_LOG_DIR} is not defined [Mon Jul 20 16:15:30.787703 2015] [core:warn] [pid 14221:tid 140466817042304] AH00111: Config variable ${APACHE_LOG_DIR} is not defined AH00526: Syntax error on line 74 of /etc/apache2/apache2.conf: Invalid Mutex directory in argument file:${APACHE_LOCK_DIR}

Then I searched some similar problem online and tried: sudo /etc/init.d/apache2 restart, it gave me:

• Restarting web server apache2 AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1. Set the 'ServerName' directive globally to suppress this message

Again, I tried to find solution online which is adding: ServerName localhost at the end of the /etc/apache2/apache2.conf

Now the sudo /etc/init.d/apache2 restart command works but the sudo apache2 still gives same error.

Could anybody help me please?

Solution

Via the following thread, try these commands that require the usage of "service":

sudo service apache2 status
sudo service apache2 start
sudo service apache2 stop
sudo service apache2 reload