Each virtual host has a subdirectory of the directory specified in the option httpd.rootdir, containing the files available to clients (browsers) connecting to that host. No file outside that directory is accessible to clients of that virtual.
Each line of the file consists of a virtual host root directory followed by the names and IP addresses of the virtual host associated with that directory. If the entry is an IP address, the named directory is associated with the given virtual host, for IP-level virtual hosting. If the entry is a name, the directory is used for the virtual host with that name, using HTTP-level virtual hosts; further, that host name is looked up and, if it resolves to an IP address used for an IP-level host alias (see the alias option in na_ifconfig(1)), that IP address is used, as if the IP address had been listed.
If the file /etc/httpd.hostprefixes is edited, it is read again by the HTTP server after the changes are saved.
/customer1 www.customer1.com /customer2 207.68.156.58
toaster> ifconfig vh alias www.customer1.com