$ gem update passenger
$ passenger-install-apache2-module --auto --languages ruby
$ passenger-install-apache2-module --snippet
LoadModule passenger_module /home/redmine/.gem/ruby/gems/passenger-6.0.10/buildout/apache2/mod_passenger.so
<IfModule mod_passenger.c>
  PassengerRoot /home/redmine/.gem/ruby/gems/passenger-6.0.10
  PassengerDefaultRuby /usr/bin/ruby
</IfModule>
$ sudo nano /etc/httpd/conf.d/redmine.tomoyan.net.conf