Patent ID: 7383313

Claim:
A distributed storage system, comprising: a first data center including a first host and a first storage subsystem that are coupled to each other via a network, the first host including a first check module configured to handle a heartbeat signal of first type, the first storage subsystem including a first storage controller and a first monitoring module, the first monitoring module being configured to handle a heartbeat signal of second type; a second data center including a second host and a second storage subsystem that are coupled to each other via a network, the second host including a second check module configured to handle the heartbeat signal of first type, the second storage subsystem including a second storage controller and a second monitoring module, the second monitoring module being configured to handle the heartbeat signal of second type; a third data center including a third storage subsystem that are coupled to each other via a network, the third host including a third check module configured to handle the heartbeat signal of first type, the third storage subsystem including a third storage controller and a third monitoring module, the third monitoring module being configured to handle the heartbeat signal of second type; a first communication network coupling the first, second, and third hosts, wherein the hosts use the first communication network to transmit or receive the heartbeat signal of first type; and a second communication network coupling the first, second, and third storage subsystems, wherein the subsystems use the second communication network to transmit or receive the heartbeat signal of second type.