Patents by Inventor Xiangping Chen

Xiangping Chen 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: 10705918
    Abstract: A storage system comprises a storage device and metadata journal comprising metadata configured to store information associated with changes to information stored on the storage device. Dirty tree (DT) metadata pages, each corresponding to information written to the storage device from the metadata journal, are stored on the storage device. DT pages are read and scanned to detect if any DT metadata page comprises an entry having an invalid snap group ID associated with a given offset. For each detected DT metadata page comprising a respective invalid snap group ID, a corresponding fake journal entry is created in metadata journal and configured to point to the respective DT metadata page comprising the invalid snap group ID and given offset. The fake journal entry is configured so that, when the metadata journal is destaged to the storage device, the invalid snap group ID is reset to nonexistent.
    Type: Grant
    Filed: July 21, 2017
    Date of Patent: July 7, 2020
    Assignee: EMC IP Holding Company LLC
    Inventors: Ying Hu, Xiangping Chen
  • Patent number: 10705914
    Abstract: An apparatus in one embodiment comprises a host device that includes at least one processor and an associated memory. The host device is configured to implement a plurality of containers each configured to access one or more portions of the memory. The containers are implemented as respective kernel control groups utilizing operating system level virtualization of the processor of the host device. The host device is further configured to assign the containers to groups in accordance with one or more designated criteria, and to generate checkpoints for respective groups of the containers. In conjunction with generation of a given one of the checkpoints for a particular one of the groups of containers, the host device identifies one or more pages of the memory that are shared by at least first and second containers of the particular group of containers, and generates the given checkpoint without duplicating the one or more shared pages to persistent storage.
    Type: Grant
    Filed: May 29, 2018
    Date of Patent: July 7, 2020
    Assignee: EMC IP Holding Company LLC
    Inventors: Junping Zhao, Xiangping Chen
  • Patent number: 10698774
    Abstract: An aspect of resolving conflicts during recovery operations includes separating journal entries for first and second types of recovery operations into each of a first and second array. For each entry in the first array, an aspect includes taking a range lock of a designated number of the addresses and creating an entry in a table. For each entry in the second array, an aspect includes upon determining a corresponding sub-LUN has been locked for an entry in the first array, incrementing a count in the table. Upon determining the corresponding sub-LUN is not locked for the entry, an aspect includes taking the address lock for the entry in the second array. An aspect further includes opening gates for a corresponding address, performing a first recovery operation corresponding to the first type of recovery operation, and performing a second recovery operation corresponding to the second type of recovery operation.
    Type: Grant
    Filed: October 31, 2018
    Date of Patent: June 30, 2020
    Assignee: EMC IP Holding Company LLC
    Inventors: Ying Hu, Xiangping Chen
  • Patent number: 10698772
    Abstract: A storage system in one embodiment is configured to participate as a source storage system in a synchronous replication process with a target storage system. In conjunction with the synchronous replication process, the source storage system receives write requests from at least one host device. Responsive to a given write request being a multi-page write request, an entry is created in a first journal, where the first journal is utilized to ensure that the given write request is completed for all of the pages or for none of the pages. Responsive to the write request being a single-page write request, an entry is created in a second journal different than the first journal. An address-to-signature table is updated utilizing write data of the write request, and if the corresponding entry for the write request was created in the first journal, the entry is swapped from the first journal into the second journal, and the write data of the write request is sent to the target storage system.
    Type: Grant
    Filed: July 17, 2018
    Date of Patent: June 30, 2020
    Assignee: EMC IP Holding Company LLC
    Inventors: Ying Hu, Xiangping Chen
  • Patent number: 10684944
    Abstract: A method is used in managing data accesses in storage systems. An access path to a storage object is evaluated. The storage object is associated with a first storage processor of a storage system for providing access to the storage object. The storage object is accessed using a second storage processor of the storage system. The storage system includes source and destination storage pools configured such that performance characteristics associated with the source storage pool is different from performance characteristics associated with the destination storage pool. The storage object resides in the source storage pool associated with the first storage processor. Based on the evaluation, the access path of the storage object is changed to the second storage processor based on a policy. The policy determines available storage space in the destination storage pool associated with the second storage processor for migrating the storage object to the destination storage pool.
    Type: Grant
    Filed: August 9, 2012
    Date of Patent: June 16, 2020
    Assignee: EMC IP Holding Company LLC
    Inventors: Khang Can, Qin Tao, Xiangping Chen, Siyu Zhou, Sadagopan Balaraman
  • Patent number: 10684926
    Abstract: In one aspect, online iterative data verification for synchronous replication is provided for a storage system that includes a source site and a target site. An aspect includes, during an active synchronous replication process between the source site and the target site, identifying inflight inputs/outputs (IOs). The inflight IOs indicate write operations that are transmitted from the source to the target but are determined to have not yet been stored at the target. A further aspect includes performing a first data verification on the source and target sites. The first data verification is performed for IOs that are not inflight IOs. An aspect also includes performing iterative data verifications during each of one or more replication cycles. The iterative data verifications verify only data written to the target site since one of the first data verification and a previously performed data verification excluding inflight IOs at the time of verification.
    Type: Grant
    Filed: October 23, 2018
    Date of Patent: June 16, 2020
    Assignee: EMC IP Holding Company LLC
    Inventors: Xiangping Chen, Svetlana Kronrod
  • Publication number: 20200183765
    Abstract: An apparatus in one embodiment comprises a host device that includes at least one processor and an associated memory. The host device is configured to implement a plurality of processes each configured to access a shared region of the memory. The host device is further configured to establish a multi-process control group for the shared region, to maintain state information for the multi-process control group, and to track usage of the shared region by the processes based at least in part on the state information. At least a subset of the processes may comprise respective containers implemented utilizing operating system level virtualization of the processor of the host device. The multi-process control group established for the shared region illustratively comprises a coarse-grained control group having a granularity greater than a single page of the shared region.
    Type: Application
    Filed: February 14, 2020
    Publication date: June 11, 2020
    Inventors: Junping Zhao, Xiangping Chen
  • Patent number: 10664268
    Abstract: An aspect of optimizing storage of data in a data replication system includes, for a plurality of write requests received from a source site, determining transfer statistics corresponding to each of the write requests and updating a table with the transfer statistics. An aspect also includes grouping pages in the table having common transfer statistics, assigning a unique non-volatile memory express (NVMe) stream identifier (ID) to each of the groups, and identifying grouped pages based on the assigned NVMe stream ID. An aspect further includes selecting a storage optimization technique for each of the groups based on the common transfer statistics and storing data of the write requests for each of the groups according to the selected optimization technique.
    Type: Grant
    Filed: October 24, 2018
    Date of Patent: May 26, 2020
    Assignee: EMC IP Holding Company LLC
    Inventors: Xiangping Chen, Junping Zhao
  • Patent number: 10664358
    Abstract: Described embodiments provide systems and methods for operating a storage system wherein an online consistent system checkpoint is generated. The checkpoint contains a point in time image of a system and is used for providing recovery of the system to a known good state. In one embodiment the checkpoint includes volume configuration data, logical volume space, a plurality of layers of metadata, and physical data storage.
    Type: Grant
    Filed: April 28, 2017
    Date of Patent: May 26, 2020
    Assignee: EMC IP Holding Company LLC
    Inventors: Xiangping Chen, Anton Kucherov, Yuval Harduf, Ying Hu, Felix Shvaiger
  • Publication number: 20200159414
    Abstract: In one aspect, support for hash based xcopy replication for synchronous replication is provided. An aspect includes determining, in response to an xcopy command, whether a source logical unit (LU) and a target LU are in active synchronous replication to the same target site. Upon determining that the LUs are in active synchronous replication, increasing a count of a hash handle list, obtaining a unique full hash digest, and sending the digest with volume replication pairing identifier, offset, and length to the target. Upon receiving a request from the source, searching, by the target, for local hash handles of the digest; and upon determining the local hash handles exist in the digest, incrementing, the reference counter handle list, and sending corresponding hash handles from the source site to the target.
    Type: Application
    Filed: January 27, 2020
    Publication date: May 21, 2020
    Applicant: EMC IP Holding Company LLC
    Inventors: Ying Hu, Xiangping Chen, Yuval Harduf, David Meiri
  • Patent number: 10642788
    Abstract: A method is disclosed comprising: generating a first snapshot of a first storage subsystem; detecting, by a management node, that all in-flight data storage requests recorded in drain tables of storage nodes in the first storage subsystem have been completed, the in-flight data storage requests recorded in the drain tables of the storage nodes being replicated in a second storage subsystem; causing, by the management node, each of the storage nodes to flip the respective designations of the tracking tables in the node's respective pair of tracking tables; and transmitting, from the management node to the second storage subsystem, an instruction which when received by the second storage subsystem causes the second storage subsystem to generate a second snapshot of the second storage subsystem.
    Type: Grant
    Filed: October 17, 2018
    Date of Patent: May 5, 2020
    Assignee: EMC IP Holding Company LLC
    Inventors: Ying Hu, Xiangping Chen
  • Publication number: 20200133798
    Abstract: An aspect of resolving conflicts during recovery operations includes separating journal entries for first and second types of recovery operations into each of a first and second array. For each entry in the first array, an aspect includes taking a range lock of a designated number of the addresses and creating an entry in a table. For each entry in the second array, an aspect includes upon determining a corresponding sub-LUN has been locked for an entry in the first array, incrementing a count in the table. Upon determining the corresponding sub-LUN is not locked for the entry, an aspect includes taking the address lock for the entry in the second array. An aspect further includes opening gates for a corresponding address, performing a first recovery operation corresponding to the first type of recovery operation, and performing a second recovery operation corresponding to the second type of recovery operation.
    Type: Application
    Filed: October 31, 2018
    Publication date: April 30, 2020
    Applicant: EMC IP Holding Company LLC
    Inventors: Ying Hu, Xiangping Chen
  • Publication number: 20200133527
    Abstract: A technique versions a configuration of data storage equipment. The technique involves receiving, while the data storage equipment operates in accordance with a first version of the configuration of the data storage equipment, a configuration change command to change the configuration of the data storage equipment. The technique further involves changing the first version of the configuration of the data storage equipment to a second version of the configuration of the data storage equipment in response to the configuration change command. The technique further involves, while the data storage equipment operates in accordance with the second version of the configuration of the data storage equipment, concurrently maintaining access to the first version of the configuration of the data storage equipment and the second version of the configuration of the data storage equipment.
    Type: Application
    Filed: October 24, 2018
    Publication date: April 30, 2020
    Inventors: Junping Zhao, Xiangping Chen
  • Publication number: 20200133668
    Abstract: An aspect of optimizing storage of data in a data replication system includes, for a plurality of write requests received from a source site, determining transfer statistics corresponding to each of the write requests and updating a table with the transfer statistics. An aspect also includes grouping pages in the table having common transfer statistics, assigning a unique non-volatile memory express (NVMe) stream identifier (ID) to each of the groups, and identifying grouped pages based on the assigned NVMe stream ID. An aspect further includes selecting a storage optimization technique for each of the groups based on the common transfer statistics and storing data of the write requests for each of the groups according to the selected optimization technique.
    Type: Application
    Filed: October 24, 2018
    Publication date: April 30, 2020
    Applicant: EMC IP Holding Company LLC
    Inventors: Xiangping Chen, Junping Zhao
  • Publication number: 20200125464
    Abstract: In one aspect, online iterative data verification for synchronous replication is provided for a storage system that includes a source site and a target site. An aspect includes, during an active synchronous replication process between the source site and the target site, identifying inflight inputs/outputs (IOs). The inflight IOs indicate write operations that are transmitted from the source to the target but are determined to have not yet been stored at the target. A further aspect includes performing a first data verification on the source and target sites. The first data verification is performed for IOs that are not inflight IOs. An aspect also includes performing iterative data verifications during each of one or more replication cycles. The iterative data verifications verify only data written to the target site since one of the first data verification and a previously performed data verification excluding inflight IOs at the time of verification.
    Type: Application
    Filed: October 23, 2018
    Publication date: April 23, 2020
    Applicant: EMC IP Holding Company LLC
    Inventors: Xiangping Chen, Svetlana Kronrod
  • Publication number: 20200125649
    Abstract: A method is disclosed comprising: generating a first snapshot of a first storage subsystem; detecting, by a management node, that all in-flight data storage requests recorded in drain tables of storage nodes in the first storage subsystem have been completed, the in-flight data storage requests recorded in the drain tables of the storage nodes being replicated in a second storage subsystem; causing, by the management node, each of the storage nodes to flip the respective designations of the tracking tables in the node's respective pair of tracking tables; and transmitting, from the management node to the second storage subsystem, an instruction which when received by the second storage subsystem causes the second storage subsystem to generate a second snapshot of the second storage subsystem.
    Type: Application
    Filed: October 17, 2018
    Publication date: April 23, 2020
    Applicant: EMC IP Holding Company LLC
    Inventors: Ying Hu, Xiangping Chen
  • Publication number: 20200125280
    Abstract: A method is disclosed comprising: generating a plurality of snapshots, each of the snapshots representing a state of one or more storage objects in a storage system; generating a plurality of access pattern records (APRs) for the storage objects, each APR being associated with a different respective one of the plurality of snapshots, each APR indicating a characteristic of workload of the storage system in a period preceding the generation of the APR's associated snapshot; detecting a workload trend for the storage objects, the workload trend being detected by using a workload prediction model that is trained based on the plurality of APRs; and configuring the storage system based on the workload trend, the configuring including allocating additional resources for servicing access requests to the storage objects when the workload trend is a rising workload trend.
    Type: Application
    Filed: October 18, 2018
    Publication date: April 23, 2020
    Applicant: EMC IP Holding Company LLC
    Inventors: Xiangping Chen, Junping Zhao
  • Publication number: 20200117750
    Abstract: In one aspect, automatic recovery of a synchronous replication session in response to an error is provided for a storage system that includes a source and target sites. During an active sync replication session in which a state machine indicates the system is operating in sync, an aspect includes monitoring input/output (IO) operations. Upon determining an occurrence of the error in which data has been persisted at the source site but not at the target site, an aspect includes discontinuing replication to the target site and transitioning the state machine from a sync state to a tripped state. Upon determining, during the tripped state, resources exist to conduct sync replication remote data transfer operations, transition the state machine to an async_to_sync state. The async_to_sync state causes the storage system to initiate a recovery operation to return the source and target sites to the sync state.
    Type: Application
    Filed: October 11, 2018
    Publication date: April 16, 2020
    Applicant: EMC IP Holding Company LLC
    Inventors: Xiangping Chen, Svetlana Kronrod
  • Patent number: 10613793
    Abstract: In one aspect, support for hash based xcopy replication for synchronous replication is provided. An aspect includes determining, in response to an xcopy command, whether a source logical unit (LU) and a target LU are in active synchronous replication to the same target site. Upon determining that the LUs are in active synchronous replication, increasing a count of a hash handle list, obtaining a unique full hash digest, and sending the digest with volume replication pairing identifier, offset, and length to the target. Upon receiving a request from the source, searching, by the target, for local hash handles of the digest; and upon determining the local hash handles exist in the digest, incrementing, the reference counter handle list, and sending corresponding hash handles from the source site to the target.
    Type: Grant
    Filed: November 1, 2018
    Date of Patent: April 7, 2020
    Assignee: EMC IP Holding Company LLC
    Inventors: Ying Hu, Xiangping Chen, Yuval Harduf, David Meiri
  • Patent number: 10606670
    Abstract: An apparatus in one embodiment comprises a host device that includes at least one processor and an associated memory. The host device is configured to implement a plurality of processes each configured to access a shared region of the memory. The host device is further configured to establish a multi-process control group for the shared region, to maintain state information for the multi-process control group, and to track usage of the shared region by the processes based at least in part on the state information. At least a subset of the processes may comprise respective containers implemented utilizing operating system level virtualization of the processor of the host device. The multi-process control group established for the shared region illustratively comprises a coarse-grained control group having a granularity greater than a single page of the shared region.
    Type: Grant
    Filed: April 11, 2018
    Date of Patent: March 31, 2020
    Assignee: EMC IP Holding Company LLC
    Inventors: Junping Zhao, Xiangping Chen