Patents by Inventor Claus William Mikkelsen
Claus William Mikkelsen 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).
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Patent number: 6789178Abstract: In a computer system, the controller of one or more primary data recording devices sends update information to the controller of one or more secondary data recording devices to maintain a remote copy of data stored on the primary data recording devices. The primary controller receives a command from a computer that specifies a prospective suspend time after which remote copy operation is to be suspended. After the suspend time passes, the primary controller stops sending the update information to the secondary controller and begins storing indicators of the updated information in cache memory. The primary controller may resume remote copy operation in response to a command received from the computer by first entering into a pending mode of operation in which cached indicators are used to identify update information that must be sent to the secondary controller to resynchronize the remote copy. When the information for all cached indicators has been sent, normal remote copy operation may be resumed.Type: GrantFiled: March 24, 2003Date of Patent: September 7, 2004Assignee: Hitachi Data Systems CorporationInventors: Claus William Mikkelsen, William David Davenport, Michael John Dutch, Cynthia Anne Martinage, Richard Allan Ruehle
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Publication number: 20030182526Abstract: In a computer system, the controller of one or more primary data recording devices sends update information to the controller of one or more secondary data recording devices to maintain a remote copy of data stored on the primary data recording devices. The primary controller receives a command from a computer that specifies a prospective suspend time after which remote copy operation is to be suspended. After the suspend time passes, the primary controller stops sending the update information to the secondary controller and begins storing indicators of the updated information in cache memory. The primary controller may resume remote copy operation in response to a command received from the computer by first entering into a pending mode of operation in which cached indicators are used to identify update information that must be sent to the secondary controller to resynchronize the remote copy. When the information for all cached indicators has been sent, normal remote copy operation may be resumed.Type: ApplicationFiled: March 24, 2003Publication date: September 25, 2003Inventors: Claus William Mikkelsen, William David Davenport, Michael John Dutch, Cynthia Anne Martinage, Richard Allan Ruehle
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Patent number: 6539462Abstract: In a computer system, the controller of one or more primary data recording devices sends update information to the controller of one or more secondary data recording devices to maintain a remote copy of data stored on the primary data recording devices. The primary controller receives a command from a computer that specifies a prospective suspend time after which remote copy operation is to be suspended. After the suspend time passes, the primary controller stops sending the update information to the secondary controller and begins storing indicators of the updated information in cache memory. The primary controller may resume remote copy operation in response to a command received from the computer by first entering into a pending mode of operation in which cached indicators are used to identify update information that must be sent to the secondary controller to resynchronize the remote copy. When the information for all cached indicators has been sent, normal remote copy operation may be resumed.Type: GrantFiled: July 12, 1999Date of Patent: March 25, 2003Assignee: Hitachi Data Systems CorporationInventors: Claus William Mikkelsen, William David Davenport, Michael John Dutch, Cynthia Anne Martinage, Richard Allan Ruehle
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Patent number: 5734818Abstract: A remote data shadowing system provides storage based, real time disaster recovery capability. Record updates at a primary site cause write I/O operations in a storage subsystem therein. The write I/O operations are time stamped and the time, sequence, and physical locations of the record updates are collected in a primary data mover. The primary data mover groups sets of the record updates and associated control information based upon a predetermined time interval, the primary data mover appending a prefix header to the record(updates thereby forming self describing record sets. The self describing record sets are transmitted to a remote secondary site wherein consistency groups are formed such that the record updates are ordered so that the record updates can be shadowed in an order consistent with the order the record updates cause write I/O operations at the primary site.Type: GrantFiled: May 10, 1996Date of Patent: March 31, 1998Assignee: International Business Machines CorporationInventors: Robert Frederic Kern, Ronald Maynard Kern, Gregory Edward McBride, William Frank Micka, Claus William Mikkelsen, David Michael Shackelford, Robert Wesley Shomler
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Patent number: 5720029Abstract: A disaster recovery system providing asynchronous remote data shadowing between a primary and a secondary site uses a pair of track arrays for each primary data storage device of a remote copy pair to monitor which record updates are in transit between the primary site and the secondary site. A host processor at the primary site of the disaster recovery system transfers a sequentially consistent order of copies of record updates to the secondary site for back-up purposes. The copied record updates are stored on the secondary data storage devices which form remote copy pairs with the primary data storage devices at the primary site. One track array, the active track array, is used to set elements according to which tracks on the primary data storage device receive record updates from the host processor at the primary site.Type: GrantFiled: July 25, 1995Date of Patent: February 17, 1998Assignee: International Business Machines CorporationInventors: Robert Frederic Kern, William Frank Micka, Claus William Mikkelsen, Robert Wesley Shomler, Warren Keith Stanley, Richard Kent Treiber
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Patent number: RE37038Abstract: A method in a data processing system for automatically terminating or resuming backup copy sessions after an abnormal interrupt or reset notification occurrence during a backup copy process. A status indication is entered into activity tables associated with a plurality of storage subsystems and devices within a data processing system in response to initiation of a backup copy session. Status indications are then entered upon successful completion of a backup copy session within the data processing system. The indications within the activity tables are reviewed to determine the status of a backup copy session upon restarting a resource manager, abnormal termination of a backup copy program, or an operating system initial program load. If a backup copy session has been initiated but not completed, the backup copy session is then terminated. The indications within the activity tables are also reviewed to determine the status of a backup copy session if a reset notification is raised by a storage subsystem.Type: GrantFiled: August 31, 1995Date of Patent: January 30, 2001Assignee: International Business Machines CorporationInventors: Lawrence E. Eastridge, Robert Frederic Kern, William Frank Micka, Claus William Mikkelsen, James Mitchell Ratliff
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Patent number: RE37364Abstract: A method and system are disclosed for enhanced efficiency of backup copying of designated datasets stored within a plurality of storage devices coupled to the data processing system via a storage subsystem control unit having subsystem memory therein. Application execution within the data processing system is temporarily suspended long enough to form a dataset logical-to-physical system address concordance to be utilized to administer copying of the designated dataset. Thereafter, application initiated updates to uncopied portions of the designated datasets are temporarily deferred until sidefiles of the affected portions of the designated datasets are written to subsystem memory. The updates are then written to the storage subsystem. Portions of the designated datasets are then accessed and copied from the storage subsystem on a scheduled or opportunistic basis utilizing selected data retrieval command sequences.Type: GrantFiled: August 31, 1995Date of Patent: September 11, 2001Assignee: International Business Machines CorporationInventors: Oded Cohn, Michael Howard Hartung, William Frank Micka, John Norbert McCauley, Jr., Claus William Mikkelsen, Kenneth Michael Nagin, Yoram Novick, Alexander Winokur