3.7.0 HP StorageWorks HP Scalable NAS File Serving Software administration guide - HP Scalable NAS 3.7 for Linux (AG513-96002, October 2009)

The following example shows the virtual host failover mechanism. Servers A and B
provide the http service, which is accessed with the virtual host www.xvz.com. Each
server is configured with an http service monitor and a custom device monitor to ping
the router.
The failover operation to another network interface has minimal impact on clients.
For example, if clients were downloading Web pages during the failover, they would
receive a “transfer interrupted” message and could simply reload the Web page. If
they were reading Web pages, they would not notice any interruption.
If the active network interface fails, only the virtual hosts associated with that interface
are failed over. If the underlying server has other virtual hosts configured on another
network interface, those virtual hosts will continue to access that server.
For more information about failover, see “Virtual hosts and failover” on page 309.
Guidelines for creating and using virtual hosts
When creating virtual hosts, follow these guidelines:
• When planning the virtual hosts needed for your cluster, first determine the network
services that will be available to your clients. Then determine the IP addresses for
those services. You will need to create a virtual host for each IP address.
• Choose virtual hostnames that differ from your actual server names. Virtual hosts
are independent of specific servers, and their names should be independent as
well.
• Use an IP address that is on the same subnet as the network interfaces where it
will be configured.
Configure virtual hosts302