Hewlett-packard Development Company, L.p.

Hewlett Packard Enterprise Development LP

Richard Fitzhugh Wrenn

David William Thiel

James Michael Reuter

Richard Perham Helliwell

Edward A Gardner

Robert George Bean

Andrew C St Martin

Andrew C Goldstein

Jeffrey Clifford Mogul

Mallikarjun Chadalapaka

Randolph B Haagens

Richard J Wagner

James E Reuter

A transmitting end-point computes a current transmission rate for each respective outbound half-route of outbound half-routes of a route set between transmitting and receiving end-points. The transmitting end-point receives, from the receiving end-point via a respective inbound half-route of the route set, a transmission rate limit for each respective outbound half-route, the transmission rate limit computed by the receiving end-point from routing headers of messages received by the receiving end-point on the respective outbound half-route, wherein the transmission rate limit for each respective outbound half-route places an upper bound on the current transmission rate for transmissions issued on the respective outbound half-route.

System and method for message routing in a network

A system and method for message routing in a computer network. The present system establishes a routing layer between the network and transport layers in a network, for communicating routing information between end-points in the network. A route management connection for communicating route management information between two ports in the network is established between pseudo end-points in the network. A route and route set are established between end-points in the network, where the route set provides a relationship between two end-point incarnations that indicates the existence of at least one route between the end-points. A route set management connection is established between the end-points for managing connections that are established on the route set. A route between the end points is selected using a route in the route set, and an application connection is established between two applications running on respective end-points in the network, using the route set and the route set management connection.

A system and method for detecting path failure in a network are described. The system and method include a network interface which receives packets over particular connections, and an agent able to monitor the network interface and start a no-traffic timer for each particular connection when a packet is received on the connection. The agent is further able, when the no-traffic timer expires, to check for outgoing data on the particular connection, and compare a count of previously sent test packets against a limit. If the count is below the limit the agent sends a new test packet on the particular connection, the test packet provides an indication of the state of a network path associated with the particular connection. If the count is above the limit the agent initiates failover procedures for the associated path.

Fast detection of path failure for TCP

A system and method for selecting a route, from within the set of network routes between the source and destination end-points, for retransmission of information initially sent via a suspected failed route such that the selected route has a minimum number of network components in common with the suspected failed route. In one aspect, the routes between source and destination end-points are grouped into a route set and placed in order in a circular list by the destination end-point. When the source end-point deems it necessary to retransmit information sent via a suspected failed route, it selects the next acceptable route following the suspected failed route from the circular list. The circular list order is determined such that adjacent routes have few common network components.

System for selecting routes for retransmission in a network

A method for controlling command message flow in a network including a server and a client. A command window, comprising a maximum number of command messages that may be outstanding at the server, is included in messages sent from the server to the client. The value of the command window at the server is modified in accordance with available server resources for receiving command messages. When there are insufficient resources at the server to process one of the command messages delivered to the server, then a pause message is sent to the client indicating which said command message cannot be received; indicia is stored that indicates the command message initially discarded; and subsequent said command messages delivered to the server are discarded until an initially discarded said command message is again delivered to the server.

Controlling command message flow in a network

A system for addressing end-points in a network wherein a transmission is sent between a source end-point and a destination end-point via a respective source port and a destination port connected by a fabric. A payload offset and buffer pool handle are included in a network header sent with the transmission. The buffer pool handle is used to determine a specific queue of pool buffers within the destination port. A pool buffer descriptor, describing a header buffer and a payload buffer each within the destination end-point, is dequeued from a queue indicated by the buffer pool handle. The payload offset in the network header is then decoded to locate a first number of bytes of data in the transmission to be transferred into the header buffer a second number of bytes of data to be transferred into the payload buffer.

System for communicating between network end-points using a payload offset and buffer pool handle

A system and method for determining route quality in a network in which multiple routes exist between a transmitting end-point and a receiving end-point. Initially, a routing sequence number is associated with each transmission sent on a route in the network, such that consecutive transmissions sent on one of the routes have consecutive routing sequence numbers. The routing sequence number for a first one of the routes is included in transmissions sent on a second one of the routes. The routing sequence number of the first route, received on the second route, is used as an indicator of the route quality of the first route, and this indicator is compared to an expected routing sequence number for the first route to determine a likelihood of whether the transmissions sent via the first route are either lost or delayed. The expected routing sequence number is normally incremented each time a transmission is received on the second route.

System for determining network route quality using sequence numbers

The present invention provides a method for copying data through a virtualized storage system using distributed table driven (I/O) mapping. In a system having a virtual disk (the 'original disk'), a persistent mapping table for this virtual disk exists on a controller, and volatile copies of some or all entries in this mapping table are distributed to one or more more mapping agents. The method of the present invention creates a new virtual disk mapping table that has the exact same entries as the mapping table as the original virtual disk. The new snapshot disk then shares the same storage as the original disk, so it is space efficient. Furthermore, creating new snapshot disk involves only copying the contents of the mapping table, not moving data, so the creation is fast. In order to allow multiple virtual disks to share storage segments, writes to either the original virtual disk or the snapshot copy cannot be seen by the other. Therefore, in addition to simply copying the mapping table, both the original and snapshot disk mapping table must also cause writes to these disks to be handled specially. Finally, any changes to the original disk mapping table stored in the controller must be coordinated with the volatile copies stored in the mapping agent in such a way so that all hosts see a consistent view of that disk.

Generating updated virtual disks using distributed mapping tables accessible by mapping agents and managed by a centralized controller

The present invention provides a system and method for creating virtualized storage in a storage area network using distributed table-driven input/output mapping. The present invention distributes the virtualization mapping in multiple parallel, mapping agents that are separate from a controller. This allows the performance-sensitive mapping process to be parallelized and distributed optimally for performance, while the control of the mapping may be located in a controller chosen for optimal cost, management, and other implementation practicalities. The mapping agents store the virtual mapping tables in volatile memory, substantially reducing the cost and complexity of implementing the mapping agents. The controller is responsible for persistent storage of mapping tables, thereby consolidating the costs and management for persistent mapping table storage in a single component. Distributed virtualization also allows the controller to manage multiple virtual disks used by multiple host systems, and allows a single virtual disk to be shared by multiple host systems. The mapping agents preferably do not interact only with other mapping agents, thereby improving the scalability of the virtual storage system and the virtual storage system's tolerance of component failures.

Architecture for parallel distributed table driven I/O mapping

A backup apparatus and method suitable for protecting the data volume in a computer system function by acquiring a base state snapshot and a sequential series of data volume snapshots, the apparatus concurrently generating succedent and precedent lists of snapshot differences which are used to create succedent and precedent backups respectively. The data volume is restored by overwriting the base state data with data blocks identified in one or more succedent backups. File recovery is accomplished by overwriting data from a current snapshot with one or more precedent backups.

Physical incremental backup using snapshots

Briefly, the present invention provides a system and method for distributing SCSI semantics throughout a network. Specifically, the present invention distributes the SCSI semantics through multiple parallel agents and a separate controller. This configuration allows performance-sensitive distribution of SCSI semantics to be parallelized and optimized for performance in the agents, while the control and management of the SCSI semantics is centralized in the controller chosen for optimal cost, management, and other implementation practicalities. In this design, the SCSI semantics are stored in the controller, and portions of the SCSI semantics are distributed to the mapping agents as cached, read-only information. The controller is responsible for persistent storage of the SCSI semantics, thereby consolidating the costs and management for the SCSI semantics in a single component. The agents preferably do not interact with other mapping agents, thereby improving the scalability of virtual storage systems and their tolerance of component failures. Within an embodiment of the SCSI distribution system, key SCSI semantic information is distributed to the agents while infrequently used semantic information is centralized in the controller. Likewise, SCSI commands that cannot be processed by the agents may be forwarded to the controller.

Structure and process for distributing SCSI LUN semantics across parallel distributed components

A computer network has two or more switches and a plurality of links. A first machine and a second machine are interconnected by the network in such a way that there exist multiple paths through the network from an N_Port of the first machine to an N_Port of the second machine. Network traffic from the N_Port of the first machine to the N_Port of the second machine is distributed between the multiple paths such that frames related to any single exchange traverse the same path yet frames of a first exchange need not traverse the same path as frames of a second exchange. Frames of each exchange therefore tend to be received by their destination in order with respect to other frames of that exchange, while they are not necessarily received in-order with respect to frames of other exchanges.

Method and apparatus for distributing traffic over multiple switched fiber channel routes

Preferred embodiments of the present invention provide a system and method for the management of virtual storage. The system and method include an object-oriented computer hardware/software model that can be presented, for example, via a management interface (e.g., via graphical user interfaces, command line interfaces, application programming interfaces, etc.). In some preferred embodiments, the model separates physical storage management from virtual disks presented to hosts and management can be automated such that the user (e.g., customer, manager and/or administrator) specifies goals rather than means&mdash;enhancing ease of use while maintaining flexible deployment of storage resources.

Growing community of inventors

Colorado Springs, CO, United States of America

Richard Fitzhugh Wrenn