Patents by Inventor David T. Tsang

David T. Tsang 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).

  • PROCESSING INPUT/OUTPUT OPERATIONS WHILE SNAPSHOT AND EXTENT COPY OPERATIONS ARE IN PROGRESS FOR A LOGICAL STORAGE VOLUME
    Publication number: 20200349020
    Abstract: An apparatus in one embodiment comprises at least one processing device having a processor coupled to a memory. The processing device is configured to maintain, for logical storage volumes of a storage system, device sequence numbers for snapshot and extent copy operations. The processing device is also configured to maintain, for at least one track of the logical storage volumes, a track sequence number representing the state of the track with respect to the snapshot and extent copy operations. The processing device is further configured to receive input/output operations directed to the logical storage volumes from host devices coupled to the storage system while at least one snapshot or extent copy operation for the logical storage volumes is in progress, and to utilize the track sequence numbers and the device sequence numbers to determine processing of the received input/output operations while the snapshot or extent copy operations are in progress.
    Type: Application
    Filed: April 30, 2019
    Publication date: November 5, 2020
    Inventors: Sandeep Chandrashekhara, David T. Tsang, Michael Ferrari, Jeffrey Wilson, Mark J. Halstead
  • Processing input/output operations while snapshot and extent copy operations are in progress for a logical storage volume
    Patent number: 10824513
    Abstract: An apparatus in one embodiment comprises at least one processing device having a processor coupled to a memory. The processing device is configured to maintain, for logical storage volumes of a storage system, device sequence numbers for snapshot and extent copy operations. The processing device is also configured to maintain, for at least one track of the logical storage volumes, a track sequence number representing the state of the track with respect to the snapshot and extent copy operations. The processing device is further configured to receive input/output operations directed to the logical storage volumes from host devices coupled to the storage system while at least one snapshot or extent copy operation for the logical storage volumes is in progress, and to utilize the track sequence numbers and the device sequence numbers to determine processing of the received input/output operations while the snapshot or extent copy operations are in progress.
    Type: Grant
    Filed: April 30, 2019
    Date of Patent: November 3, 2020
    Assignee: EMC IP Holding Company LLC
    Inventors: Sandeep Chandrashekhara, David T. Tsang, Michael Ferrari, Jeffrey Wilson, Mark J. Halstead