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

i'm new apache2, , i'm trying apache2 running on local linux (linux mint 17). when try to: sudo apache2, gives me following error:

[mon jul 20 16:15:30.785526 2015] [core:warn] [pid 14221] ah00111: config variable ${apache_lock_dir} not defined [mon jul 20 16:15:30.785602 2015] [core:warn] [pid 14221] ah00111: config variable ${apache_pid_file} not defined [mon jul 20 16:15:30.785618 2015] [core:warn] [pid 14221] ah00111: config variable ${apache_run_user} not defined [mon jul 20 16:15:30.785627 2015] [core:warn] [pid 14221] ah00111: config variable ${apache_run_group} not defined [mon jul 20 16:15:30.785644 2015] [core:warn] [pid 14221] ah00111: config variable ${apache_log_dir} not defined [mon jul 20 16:15:30.787550 2015] [core:warn] [pid 14221:tid 140466817042304] ah00111: config variable ${apache_log_dir} not defined [mon jul 20 16:15:30.787686 2015] [core:warn] [pid 14221:tid 140466817042304] ah00111: config variable ${apache_log_dir} not defined [mon jul 20 16:15:30.787703 2015] [core:warn] [pid 14221:tid 140466817042304] ah00111: config variable ${apache_log_dir} not defined ah00526: syntax error on line 74 of /etc/apache2/apache2.conf: invalid mutex directory in argument file:${apache_lock_dir}

then searched similar problem online , tried: sudo /etc/init.d/apache2 restart, gave me:

• restarting web server apache2 ah00558: apache2: not reliably determine server's qualified domain name, using 127.0.1.1. set 'servername' directive globally suppress message

again, tried find solution online adding: servername localhost @ end of /etc/apache2/apache2.conf

now sudo /etc/init.d/apache2 restart command works sudo apache2 still gives same error.

could me please?

try: sudo service apache2 {command} instead of {}'s enter 1 of following options:

• start
• restart
• stop
• status