Patents by Inventor Michael B. Evans

Michael B. Evans has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9081691
    Abstract: Described are techniques for performing recovery processing in a data storage system. A providing a flash-based memory is provided with includes cached write data that has not been destaged to a data storage device. It is determined whether said flash-based memory has a threshold amount of storage available thereon. If the flash-based memory does not have the threshold amount of storage available thereon, portions of the cache write data are destaged until said flash-based memory has a threshold amount of storage available thereon. Received data requests are processed in accordance with a first policy different from a second policy used in connection with processing received data requests if said flash-based memory has a threshold amount of storage available thereon.
    Type: Grant
    Filed: September 21, 2012
    Date of Patent: July 14, 2015
    Assignee: EMC Corporation
    Inventors: Uday K. Gupta, Charles H. Hopkins, Michael B. Evans
  • Patent number: 8473566
    Abstract: Methods, systems, and computer program products for managing quality of service for shared storage accessed by a plurality of nodes are disclosed. According to one method, at a node of a plurality of nodes sharing access to a first disk array, quality-of-service (QoS) metadata associated with a portion of the disk array are requested from a server, wherein the QoS metadata includes at least one performance criterion for the portion of the disk array. I/O performance is monitored for the portion of the disk array in response to receiving the QoS metadata. The monitored I/O performance is compared with the QoS metadata. Based upon the comparison of the monitored I/O performance with the QoS metadata, it is determined whether a QoS violation has occurred. In response to determining that a QoS violation has occurred, the server is requested to migrate data associated with the portion of the disk array.
    Type: Grant
    Filed: June 30, 2006
    Date of Patent: June 25, 2013
    Assignee: EMC Corporation
    Inventors: John T. Cardente, James T. Compton, Michael B. Evans, Stephen A. Fridella, Uday K. Gupta
  • Patent number: 8392370
    Abstract: A method is used in managing data on data storage systems. Rules are defined for candidate data unit selection. The rules are automatically executed on a primary data storage system to examine data units on the primary data storage system. The rules are applied to the data units. A data unit is identified that matches the rules and the identified data unit is migrated. The identified data unit is copied from the primary storage system to a secondary storage system. The identified data unit on the primary storage system is replaced with metadata. the data storage space in the primary storage system corresponding to the identified data unit is freed up.
    Type: Grant
    Filed: March 28, 2008
    Date of Patent: March 5, 2013
    Assignee: EMC Corporation
    Inventors: William Whitney, Uday K. Gupta, Michael B. Evans, Gerald E. Cotter
  • Patent number: 8296534
    Abstract: Described are techniques for performing recovery processing in a data storage system. A providing a flash-based memory is provided with includes cached write data that has not been destaged to a data storage device. It is determined whether said flash-based memory has a threshold amount of storage available thereon. If the flash-based memory does not have the threshold amount of storage available thereon, portions of the cache write data are destaged until said flash-based memory has a threshold amount of storage available thereon. Received data requests are processed in accordance with a first policy different from a second policy used in connection with processing received data requests if said flash-based memory has a threshold amount of storage available thereon.
    Type: Grant
    Filed: June 29, 2007
    Date of Patent: October 23, 2012
    Assignee: EMC Corporation
    Inventors: Uday K. Gupta, Charles H. Hopkins, Michael B. Evans
  • Patent number: 7793061
    Abstract: Described are techniques for managing data in a data storage system. While the data storage system is operating in a first mode, portions of cached write data not yet destaged to a data storage device are copied from the volatile memory cache to a first area in a flash-based memory. In response to a vault operation event, the data storage system operates in a second mode in which all remaining portions of cached write data from the volatile memory cache not currently included in the first area are copied to a second area of the flash-based memory.
    Type: Grant
    Filed: June 29, 2007
    Date of Patent: September 7, 2010
    Assignee: EMC Corporation
    Inventors: Uday K. Gupta, Charles H. Hopkins, Michael B. Evans
  • Patent number: 5671225
    Abstract: In a distributed interactive multimedia service system, a client application of a set-top box located at a customer premises generates an attach request. A session manager, in response to receiving the attach request via a network, generates an allocation request and a create request. A resource manager, in response to the allocation request, allocates resources of a plurality of multimedia servers. The resources can include processor, memory, disk, and network resources. A media stream manager, in response to the create request, creates a multimedia stream. The session manager, in response to the resources being allocated, and the multimedia stream being created, launches a selected one of a plurality of multimedia services in the plurality of multimedia servers. The selected service provides multimedia information to the set-top box via the multimedia stream.
    Type: Grant
    Filed: September 1, 1995
    Date of Patent: September 23, 1997
    Assignee: Digital Equipment Corporation
    Inventors: Donald F. Hooper, Dave M. Tongel, Michael B. Evans
  • Patent number: 5313623
    Abstract: Methods and apparatus for immunizing dynamic random access memory (DRAM) modules in the data processing system against data loss from transitions that occur with memory mode switching during the scan operation and permitting normal operations to be performed on the memory modules regardless of the state of the system clocks.
    Type: Grant
    Filed: July 3, 1990
    Date of Patent: May 17, 1994
    Assignee: Digital Equipment Corporation
    Inventors: Kumar Chinnaswamy, Hansel A. Collins, Michael B. Evans, Timothy P. Fissette, Michael A. Gagliardo, John J. Lynch, James E. Tessari
  • Patent number: 5255381
    Abstract: Methods and apparatus for immunizing dynamic random access memory (DRAM) modules in the data processing system against data loss from transitions that occur with memory mode switching during the scan operation and permitting normal operations to be performed on the memory modules regardless of the state of the system clocks.
    Type: Grant
    Filed: September 14, 1990
    Date of Patent: October 19, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Kumar Chinnaswamy, Hansel A. Collins, Michael B. Evans, Timothy P. Fissette, Michael A. Gagliardo, John J. Lynch, James E. Tessari
  • Patent number: 5146564
    Abstract: A computer system includes a plurality of central processing units (CPUs), a main memory, a system control unit (SCU) for controlling the transfer of data between the CPUs and the main memory, and a service processing unit (SPU) to interface the computer system with the outside world, such as an operator console. The method used for interfacing the SPU and SCU includes delivering a BUFFER FULL handshaking signal from the SPU to the SCU in response to the SPU receive buffer having data contained therein and being unavailable to receive data. The SCU responds to the absence of the BUFFER FULL handshaking signal by delivering a TRANSMIT FRAME handshaking signal to the SCU. A preselected duration of time after delivering the transmit frame, the SCU delivers the actual data in a series of fourteen consecutive clock cycles.
    Type: Grant
    Filed: February 3, 1989
    Date of Patent: September 8, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Michael B. Evans, Rueysen Lin, Brian F. Rost, R. Stephen Polzin
  • Patent number: 4982402
    Abstract: In a multiprocessor system, an error occurring in any one of the CPUs may have an impact upon the operation of the remaining CPUs, and therefore these errors must be handled quickly. The errors are grouped into two categories: synchronous errors (those that must be corrected immediately to allow continued processing of the current instruction); and asynchronous errors (those errors that do not affect execution of the current instruction and may be handled upon completing execution of the current instruction). Since synchronous errors prevent continued execution of the current instruction, it is preferable that the last stable state conditions of the faulting CPU be restored and the faulting instruction reexecuted. These stable state conditions advantageously occur between the execution of each instruction. However, in a pipelined computer system, it is difficult to identify the beginning and ending of a selected instruction since multiple instructions are in process at the same time.
    Type: Grant
    Filed: February 3, 1989
    Date of Patent: January 1, 1991
    Assignee: Digital Equipment Corporation
    Inventors: Richard C. Beaven, Michael B. Evans, Tryggve Fossum, Ricky C. Hetherington, William R. Grundmann, John E. Murray, Ronald M. Salett