源自：https://access.redhat.com/solutions/1381343

故障描述：

-- Unit httpd.service has begun starting up.
Apr 19 22:20:40 centreon-upgrade-test httpd[4793]: httpd: Syntax error on line 153 of /etc/httpd/conf/httpd.conf: Cannot load modules/mod_authn_alias.so into server: /etc/httpd/modules/mod_authn_alias.so: cannot open shared object file: No such file or directory
Apr 19 22:20:40 centreon-upgrade-test systemd[1]: httpd.service: Main process exited, code=exited, status=1/FAILURE
Apr 19 22:20:40 centreon-upgrade-test systemd[1]: httpd.service: Failed with result 'exit-code'.
-- Subject: Unit failed
-- Defined-By: systemd
-- Support: https://access.redhat.com/support
-- 
-- The unit httpd.service has entered the 'failed' state with result 'exit-code'.
Apr 19 22:20:40 centreon-upgrade-test systemd[1]: Failed to start The Apache HTTP Server.

解决方案：

以前的Apache httpd 2.2中mod_authn_alias模块提供的功能。X版本已移至mod_authn_core.so。由于这个mod_authn_alias。所以模块不存在Apache httpd 2.4.6在RHEL7。删除/注释任何加载mod_authn_alias的配置。在httpd.conf文件中重新启动Apache httpd服务。

例如：

# LoadModule authn_alias_module modules/mod_authn_alias.so