restart apache:
apachectl -k restart -f httpd.conf
stop apache:
apachectl -k graceful
DocumentRoot /usr/web
<Directory "/usr/web"> Options Indexes MultiViews AllowOverride None Order allow,deny Allow from all</Directory>
这样就设置了http的根目录为 /usr/web 且 用户可以访问
then an access to http://www.my.host.com/index.html refers to /usr/web/index.html
