Virtual hosts in WebSphere

Virtual hosts let you manage a single Application Server on a single machine as if the Application Server were multiple Application Servers each on their own host machine. Resources associated with one virtual host cannot share data with resources associated with another virtual host, even though the virtual hosts share the same Application Server on the same physical machine.
Virtual hosts allow the administrator to isolate, and independently manage, multiple sets of resources on the same physical machine.

http://publib.boulder.ibm.com/infocenter/wasinfo/v5r1//index.jsp?topic=/com.ibm.websphere.base.doc/info/aes/ae/tcws_plugin_vhost.html

当应用程序部署在WAS上，IP、host等等都是对的，却发现页面不存在，可以检查下是否配置的Virtual host 对不对。
Admin console -> Environment -> Virtual Hosts 里面有不同的virtual host 对应的一组Web access ports。