International Business Machines Corporation

Other

Robert J Gallagher

Karl H Hoppe

Harry M Yudenfriend

William J Rooney

Eugene P Hefferon

Mark Steven Styduhar

Michael E O'Donnell

Martin W Sachs

Anthony J Perri

Richard Cwiakala

Anthony S Coscarella

Michael C Cox

Jordan M Taylor

Peter M Holmes

Bert W Weidle

Gary A Fisher, Sr

Jean-Louis Fava

Peter I Kania

A method, apparatus, and computer program device enabling a computer network switching device to inform an attached requesting device of switch ports affected by configuration changes during the period of time since the last query by the particular requesting device. The switch device is initialized with a change index and data vector, the latter indicative of an initial port configuration. The switch increments the index in response to subsequent port configuration change events, and stores in association with the incremented index a data vector indicating the ports changed during the corresponding event. The switch stores an array of associated index and vector values. The switch responds to a query from an attached requesting device by informing the requesting device of specific ports affected by one or more configuration changes since the index value held by the requesting device was the current index value in the switch.

Method, apparatus and computer program for informing a requesting device of port configuration changes in a computer network switching device

An in-band method/apparatus whereby a host is enabled to secure predetermined operational information relative to predetermined ports of a fiber channel switch. A set command is generated at the host and sent in-band to the switch. The information content of the set command defines the ports for which operational-parameters are to be monitored. The information content of the set command also defines which operational parameters are to be monitored. In response to receiving the set command, the switch establishes statistical counters for monitoring port operational parameters in accordance with received operational parameter identifiers. An accept signal is then sent in-band to the host, and a time period of port monitoring begins. After a predefined time period has expired, the host sends a read command in-band to the switch. The switch now generates a monitor record in accordance with the count content of the statistical counters that were established in response to the set command. This monitor record contains one port field for each of the ports that were specified by the set command, and each of the port fields contains one or more count fields that contain port operational count data for the port operational parameters that were specified by the set command. The monitor record is then sent in-band to the host. Recycling of the timed process may be provided.

In-band method and apparatus for reporting operational statistics relative to the ports of a fibre channel switch

A central time-of-day reference is integrated into a switch which interconnects I/O devices and host processors in a computer complex via fiber-optic links. A time reference oscillator in the switch serves to generate incrementing reference signals for the central reference and also provides a clock signal for the switch transmissions. Units to which the switch is attached obtain clock signals from their regenerated clocks which are synchronized to the time reference oscillator, and use the regenerated clock signals to control their local time-of-day references. Each unit periodically transmits a signal to the switch requesting a dynamic connection to the switch-based central time-of-day reference in order to receive a time of day message.

Method and apparatus for synchronizing plural time-of-day (TOD) clocks

An inexpensive and low power consumption power control unit that does not require a separate interface or network. In the power off state only a detector and a power controller require power, this power is supplied from a power source. Upon detection of traffic a frame decoder is powered up to receive frames. When the link is quiet, the decoder is powered down while the power controller and receiver remain powered and await further traffic.

Remote power control via data link

A computer system, including at least one host (processor and operating system), a channel subsystem and at least one switch (together with an associated switch controller) for switchably connecting an I/O device (together with an associated I/O device control unit) to a host via said channel subsystem, in combination with means for dynamically managing I/O connectivity in said computer from each host. The I/O manager's functions are centralized at the host level across the computer system. Each host is responsible for an instance of the manager. According to the preferred embodiment of the invention the computer system, I/O manager combination includes: (a) first means, located within each switch, for providing direct host access to the switch controller associated with a given switch; (b) second means, included in each host level instance of the manager, for automatically and dynamically determining the current I/O configuration and connectivity of each host; (c) third means, included in each host level instance of the manager, for performing System Integrated Switching (i.e., switching where any instance of the I/O manager can veto a proposed configuration change) and (d) fourth means, included in each host level instance of the manager, for insuring the integrity of the I/O connectivity database, through the use of an interlock mechanism, in a multiuser environment where each user can enter multiple part commands and processes concurrently.

Methods and apparatus for dynamically managing input/output (I/O)

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Hurley, NY, United States of America

Robert J Gallagher