Debuggingdebugging using the apachectl commandDirectivesDocumentRoot directiveErrorDocument directive (401 404 500)Listen directivePID (process ID)Require ip directive (whitelist)Virtual HostsHTTPS / SSLHTTPS / SSLInstallCheck configuration using the apachectl commandCheck configuration using the httpd commandInstall Apache on LinuxInstall HTTPD in LinuxLogsaccess log (CustomLog)Create a custom logerror_logMIMEMIME types for videoModulesDisplay loaded modules using the apachectl commandDisplay loaded modules using the httpd commandPHPHide .php extension with HTTPD web serverInstall PHP on LinuxPortsPortsProxy PassLoad Balance Proxy PassStart Stop RestartStart Stop Restart web server using the apachectl commandTroubleshootingResolve "AH01144: No protocol handler was valid for the URL. If you are using a DSO version of mod_proxy make sure the proxy submodules are included in the configuration using LoadModule"Resolve "AH01150 Ignoring parameter because of worker sharing"Resolve "cannot load module"Resolve "cannot open shared object file"Resolve "cannot use a full URL in ErrorDocument directive" (401 404 500)Resolve "No space left on device AH00023 Couldn't create the mutex" on LinuxResolve "Segmentation fault"Resolve "site can't be reached, unable to connect"Resolve 401 (unauthenticated)Resolve 404 Not FoundVirtual HostsVirtual Hosts