title: AH00526: Syntax error on line 74 of /etc/apache2/apache2.conf: Invalid Mutex directory in argument file:${APACHE_LOCK_DIR}
body: <p>I'm new to Apache2, and I'm trying to get Apache2 running on my local Linux (linux mint 17). When I try to: <strong>sudo apache2</strong>, it gives me following error:</p>
  
  <blockquote>
    <p>[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}</p>
  </blockquote>
  
  <p>Then I searched some similar problem online and tried: <strong>sudo /etc/init.d/apache2 restart</strong>, it gave me:</p>
  
  <ul>
  <li>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</li>
  </ul>
  
  <p>Again, I tried to find solution online which is adding: <strong>ServerName localhost</strong> at the end of the <strong>/etc/apache2/apache2.conf</strong></p>
  
  <p>Now the <strong>sudo /etc/init.d/apache2 restart</strong> command works but the <strong>sudo apache2</strong> still gives same error. </p>
  
  <p>Could anybody help me please?</p>