Emc Corporation

Stephen D MacArthur

David Lionel Black

Richard Wheeler

Robert A Thibault

Brett D Niver

William F Baxter

Yechiel Yochai

Avinash Kallat

Man Min Moy

Natan Vishlitzky

Yuval Ofek

Steven T McClure

Brian William Gallagher

Steven R Chalmer

Michael Sgrosso

Paul C Wilson

Rudy M Bauer

William Frederick Baxter, Iii

Michael Shulman

Alexander Y Aronov

Brian Marchionni

A data storage system having a packet switching network, a cache memory, and a plurality of directors, one portion of such directors being adapted for coupling to a host computer/server and another portion of the directors being adapted for coupling to a bank of disk drives. The plurality of directors and cache memory are interconnected through the packet switching network. Each one of the directors is adapted to transmit different types of information packets to another one of the directors through the network. Each one of the directors is adapted to transmit and receive different types of information packets to another one of the directors or cache memories through the packet switching network. Each one of the cache memories is adapted to receive and transmit different types of information packets to one of the directors through the packet switching network. One type of information packet requires a different degree of latency than another type of information packet. The system includes an arbiter for transmitting the information packets as a function of the latency requirement, a priority assigned to the information packet, and the age of such information packets having been stored in a queue of the transmitting one of the directors, the packet switching network, or one of the cache memories.

Data storage system having packet switching network with latency arbitration

Described is an end-to-end broadcast-based messaging technique used in controlling message flow in a data storage system. Each node stores flow control state information about all the nodes which is used in determining whether to send a data transmission to a receiving node. The flow control state information includes an indicator as to whether each node is receiving incoming data transmissions. If a node is not receiving incoming data transmissions, the flow control state information also includes an associated expiration time. Data transmissions are resumed to a receiving node based on the earlier of a sending node determining that the expiration time has lapsed, or receiving a control message from the receiving node explicitly turning on data transmissions. Each node maintains and updates its local copy of the flow control state information in accordance with control messages sent by each node to turn on and off data transmissions. Each node sends out control messages in accordance with predetermined threshold levels taking into account hardware and/or software resources for message buffering.

End-to-end broadcast based flow control in a switch fabric

An end point controller includes two of ingress/egress port pairs. A first one of the ingress/egress ports is adapted to send and receive one of a pair of types of information packets and a second one of the ingress/egress ports is adapted to send and receive the other one of the pair of types of information packets. A controller is coupled to the two port pairs for coupling one of ingress/egress ports to an input/output port selectively in accordance with the type of the information packet on the ingress/egress ports and the availability of the end point controller to a network. One of the egress ports is directly coupled to the output port to the network if the information packet is at such port and the end point controller has been granted access to the network while other information at the pair of egress ports is buffered prior to being coupled to the output. In like fashion, the input port from the network is directly coupled to one of the ingress ports if the information packet is of the type of information packet destined for such ingress port, said port being available to transmit the packet.

Packet switching network end point controller

A method is provided for performing arbitration in an information packet controller. The method includes transmitting different types of information packets from an initiator to a receiver. One type of information packet has a quality of service requiring a faster transmission time from the initiator to the receiver than another type of information packet having a quality of service having a slower transmission time from the initiator to the receiver. The transmitting of the information packets from the initiator to the receiver is in accordance with priority assigned to the information packet, the quality of service assigned to the information packet, and the age of such information packets having been stored in a queue of the initiator, such quality of service being a function of the speed at which the packets are required to pass from the initiator to a receiver.

Arbitration method and system

An assembly couples first and second backplanes together. The first backplane is configured to carry first electrical backplane signals among a first set of circuit boards. The second backplane is configured to carry second electrical backplane signals among a second set of circuit boards. The assembly includes a first switch configured to convey at least some of the first electrical backplane signals between circuit boards of the first set of circuit boards. The assembly further includes a second switch configured to convey at least some of the second electrical backplane signals between circuit boards of the second set of circuit boards. The assembly further includes a fiber optic cable joining the first and second switches together. The first and second switches are configured to exchange fiber optic signals through the fiber optic cable thus forming a cohesive backplane interconnect system between the first and second sets of circuit boards.

Methods and apparatus for forming a cohesive backplane interconnect system

A system interface includes a plurality of first directors, a plurality of second directors, a data transfer section and a message network. The data transfer section includes a cache memory. The cache memory is coupled to the plurality of first and second directors. The messaging network operates independently of the data transfer section and such network is coupled to the plurality of first directors and the plurality of second directors. The first and second directors control data transfer between the first directors and the second directors in response to messages passing between the first directors and the second directors through the messaging network to facilitate data transfer between first directors and the second directors. The data passes through the cache memory in the data transfer section. A method for operating a data storage system adapted to transfer data between a host computer/server and a bank of disk drives. The method includes transferring messages through a messaging network with the data being transferred between the host computer/server and the bank of disk drives through a cache memory, such message network being independent of the cache memory.

Method for message transfer in computer storage system

Data storage system having separate data transfer section and message network having bus arbitration

A system interface having a plurality of first directors and a crossbar switch having input/output ports coupled to the first directors on such one of the first director boards and a pair of output/input ports. A plurality of second director boards is provided. Each one of the second directors boards has a plurality of second directors a crossbar switch having input/output ports coupled to the second directors on such one of the second director boards and a pair of output/input ports. A data transfer section is provided having a cache memory. The cache memory is coupled to the plurality of first and second directors. A message network is provided, such network being operative independently of the data transfer section. The first and second directors control data transfer between the first directors and the second directors in response to messages passing between the first directors and the second directors through the message network to facilitate data transfer between first directors and the second directors. The data passes through the cache memory in the data transfer section. Each one of the directors includes a data pipe coupled between an input of such one of the first directors and the cache memory; a microprocessor. A controller is coupled to the microprocessor and the data pipe for controlling the transfer of the messages between the message network and such one of the first directors and for controlling the data between the input of such one of the first directors and the cache memory.

Data storage system having separate data transfer section and message network with plural directions on a common printed circuit board

A system interface includes a plurality of first director boards. Each one of the first director boards has a plurality of first directors and a crossbar switch having input/output ports coupled to the first directors on such one of the first director boards and a pair of output/input ports. The system interface also includes a plurality of second director boards. Each one of the second directors boards has a plurality of second directors and a crossbar switch having input/output ports coupled to the second directors on such one of the second director boards and a pair of output/input ports. A data transfer section is provided having a cache memory. The cache memory is coupled to the plurality of first and second directors. A message network is operative independently of the data transfer section. The message network includes a pair of message network boards. Each one of such message network boards has a switching network having a plurality input/output ports. Each one of such pair of input/output ports is coupled to a corresponding one of the pair of output/input ports of the crossbar switches of the plurality of first director boards and the plurality of second director boards. The first and second directors control data transfer between the first directors and the second directors in response to messages passing between the first directors and the second directors through the message network to facilitate data transfer between first directors and the second directors. Data passes through the cache memory in the data transfer section. Each one of the directors includes: a data pipe coupled between an input of such one of the second directors and the cache memory; a microprocessor. A controller is coupled to the microprocessor and the data pipe for controlling the transfer of the messages between the message network and such one of the second directors and for controlling the data between the input of such one of the second directors and the cache memory.

Data storage system having separate data transfer section and message network with plural directors on a common printed circuit board and redundant switching networks

A data storage system for transferring data between a host computer/server and a bank of disk drives through a system interface. The system interface includes: a plurality of first directors coupled to the host computer/server; a plurality of second directors coupled to the bank of disk drives; a cache memory; and a data transfer section coupled to the plurality of first directors, the second directors, and the cache memory. A messaging network is coupled to the plurality of first directors and the plurality of second directors. The first and second directors control data transfer between the host computer and the bank of disk drives in response to messages passing between the directors through the messaging network as such data passes through the memory via the data transfer section. A service processing network is provided for interfacing a plurality of service processing units to the plurality of first and second directors through a plurality of redundant communication channels. With such arrangement, because the service processor is being more involved in the functionality operation of the system, a pair of redundant service processors is provided. This thereby improves the reliability of the system including those system functions controlled by the service processor.

Data storage system having redundant service processors

Data storage system having multi-cast/unicast

Data storage system having separate data transfer section and message network with status register

Data storage system having separate data transfer section and message network with pointer or counters

A controller for providing buffering between a data source/destination and a network. The network is coupled to the controller through an Ethernet bus. The controller includes an Ethernet MAC Core coupled to the Ethernet bus. A buffer is disposed between the MAC Core and the data source/destination for storing data/control frames. Each frame has an Ethernet data portion and an Ethernet MAC Core control signal portion to reduce central processing unit overhead in processing transmission and reception of Ethernet frame data. A control section enables the frames to pass between the source/destination and the network through the MAC Core under control of the buffer stored Core control signals portion of the frame.

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Northboro, MA, United States of America

Stephen D MacArthur