This is very helpful, when you are trying out different layout for your website and don’t want to modify the original files under the default DocumentRoot.
Take a copy of your original DocumentRoot directory (/var/www/html) to a new temporary DocumentRoot directory (/var/www/html_debug). Make all your changes under this temporary DocumentRoot directory (/var/www/html_debug) and start the Apache with this temporary directory as shown below using option -c.
# httpd -k start -c “DocumentRoot /var/www/html_debug/”
If you want to go back to original configuration using the default DocumentRoot (/var/www/html), simply restart the Apache as shown below.
# httpd -k stop # apachectl start