ACTIVE POWER MANAGEMENT FOR A COMPUTER SYSTEM

摘要

The present invention provides a method and apparatus for actively managing the overall power consumption of a computer network which includes a plurality of computer systems interconnected to each other. In turn, each computer system has one or more modules. Each computer system of the computer network is capable of independently initiating a transition into a powerconserving mode, i.e., a "sleep" state, while keeping its network interface "alive" and fully operational. Subsequently, each computer system can independently transition back into a fully operational state, i.e., an "awake" state, when triggered by either a deterministic or an asynchronous event. As a result, the sleep states of the computer systems are transparent to the computer network. Deterministic events are events triggered internally by a computer system, e.g., an internal timer waking the computer system up at midnight to perform housekeeping chores such as daily tape backups. Conversely, the source of asynchronous events are external in nature and include input/ output (I/O) activity. The illusion of the entire network being always fully operational is possible because the system controllers, the interconnects and network interfaces of each computer system remain fully operational while the selected modules and peripheral devices are powered down. As a result, each computer system is able to rapidly wake up from the sleep state in response to stimuli by powering down selected modules thereby accomplishing power conservation without requiring a static shutdown of the computer network, i.e., without affecting the overall performance and response of the computer network.