Abstract: A method of providing high availability of a service includes the step of allocating the service and a shared volume of a first mass storage device associated with the service to a first server of a first subcluster that is located at a first site and that includes servers which share the first mass storage device. Another step of the method includes mirroring the shared volume to a second mass storage device of a second subcluster that is located at a second site and that includes at least one server in order to obtain a first mirrored copy of the shared volume at the second site. Yet another step of the method includes determining to reallocate said service to a first server of the second subcluster. The method also includes the step of allocating the first mirrored copy to the first server of the second subcluster.

Abstract: A method and apparatus are disclosed which perform a simple check of the network adapter by sending a message to an address of a local adapter. If the message is not sent, then a more in depth check of the network is performed. The local computer sends a request to a first remote computer to ping the adapter on the local computer. If this ping is successful, then the local computer sends a request to a second remote computer to ping the adapter on the local computer. The pinging by two computers provides confirmation that the network adapter is functional. If both of the pings are unsuccessful, then the address of the network adapter is moved to another adapter on another computer.

Abstract: A protocol for a high availability (HA) computer cluster. The protocol provides an open standard for various platforms and HA application software and provides such features as automatic message resend, communication path analysis and prioritization, independent heartbeat signal monitoring, routing, security and automatic configuration.