HP StorageWorks Clustered File System 3.6.0 Windows Storage Server Edition Administration Guide (403103-005, January 2008)

Chapter 15: Configure Virtual Hosts 186
When certain events occur on the server where a virtual host is located,
the ClusterPulse process will attempt to fail over the virtual host to
another server configured for that virtual host. For example, if the server
goes down, ClusterPulse will check the health of the other servers and
then determine the best location for the virtual host.
ClusterPulse uses the following virtual-host activeness policy to
determine the server where it will make a virtual host active. In
conjunction with this policy, the decisions that you make when
configuring a virtual host and the service or device monitors associated
with it help determine whether virtual host failover occurs, the interface
to which the virtual host will fail over, and what happens when
operations are restored on the original server.
Virtual Host Activeness Policy
The policy described here is accurate for this release but it may change in
future releases.
The virtual host activeness policy decision is made as follows:
1. If the virtual host is disabled, it is not made active anywhere.
2. ClusterPulse considers the list of servers that are both up and enabled
and that are configured for the virtual host. The network interface that
the virtual host is associated with must also be both up and enabled
for hosting. Note the following:
• A server that has not finished joining the cluster (see “Server
Access to the SAN” on page 235) is not considered up for the
purpose of activating the device monitor.
• A server is considered down if it loses coordinated communication
with the cluster (for example, the server crashed or was shut down,
HP Clustered File System was shut down on that server, the server
failed to schedule a cluster group communication process for an
extended period of time, the server disabled the NIC being used
for cluster network traffic, and so on).