Patents by Inventor Ling Zheng

Ling Zheng 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).

  • Publication number: 20160070714
    Abstract: A low-overhead merge technique enables restart of a merge operation with minimal logging of state information relating to progress of the merge operation by a volume layer of a storage input/output (I/O) stack executing on one or more nodes of a cluster. The technique enables restart of the merge operation by ensuring that metadata, i.e., metadata pages, generated during the merge operation is not subject to de-duplication by providing a unique value in each metadata page that distinguishes the page, i.e., renders the page distinct or “unique”, from other metadata pages in an extent store. In addition, the technique ensures that a reference count on each metadata page is a value denoting a lack of de-duplication. To that end, the extent store layer is configured to not increment the reference count for a metadata page if, during the merge operation, the page is identical (and thus subject to deduplication) to an existing metadata page in the extent store.
    Type: Application
    Filed: September 10, 2014
    Publication date: March 10, 2016
    Inventors: Janice D'Sa, Anshul Pundir, Srinath Krishnamachari, Ling Zheng
  • Publication number: 20160070644
    Abstract: An offset range striping technique increases concurrency of operation execution directed to metadata managed by a volume layer of a storage input/output (I/O) stack, while reducing contention among resources of one or more nodes of a cluster. A logical unit (LUN) may be apportioned into multiple volumes, each of which may be partitioned into multiple regions, wherein each region is represented by a dense tree. The technique increases concurrency of operation execution (e.g., modifications to the metadata at the offset ranges), while reducing contention among the resources (e.g., CPUs and NVLogs) by distributing the offset range operations among the regions and mapping the regions to services and NVLogs. Such increased concurrency and reduction of contention may be achieved by implementation of the technique to (i) apportion each region into disjoint chunks (i.e.
    Type: Application
    Filed: September 10, 2014
    Publication date: March 10, 2016
    Inventors: Janice D'Sa, Anshul Pundir, Srinath Krishnamachari, Ling Zheng, Jeffrey S. Kimmel
  • Publication number: 20160070618
    Abstract: Embodiments herein are directed to efficient crash recovery of persistent metadata managed by a volume layer of a storage input/output (I/O) stack executing on one or more nodes of a cluster. Volume metadata managed by the volume layer is organized as a multi-level dense tree, wherein each level of the dense tree includes volume metadata entries for storing the volume metadata. When a level of the dense tree is full, the volume metadata entries of the level are merged with the next lower level of the dense tree. During a merge operation, two sets of generation IDs may be used in accordance with a double buffer arrangement: a first generation ID for the append buffer that is full (i.e., a merge staging buffer) and a second, incremented generation ID for the append buffer that accepts new volume metadata entries. Upon completion of the merge operation, the lower level (e.g., level 1) to which the merge is directed is assigned the generation ID of the merge staging buffer.
    Type: Application
    Filed: September 10, 2014
    Publication date: March 10, 2016
    Inventors: Anshul Pundir, Janice D'Sa, Srinath Krishnamachari, Ling Zheng
  • Patent number: 9280571
    Abstract: A method performed in a system that has a plurality of volumes stored to storage hardware, the method including generating, for each of the volumes, a respective space saving potential iteratively over time and scheduling space saving operations among the plurality of volumes by analyzing each of the volumes for space saving potential and assigning priority of resources based at least in part on space saving potential.
    Type: Grant
    Filed: August 14, 2014
    Date of Patent: March 8, 2016
    Assignee: NetApp, Inc.
    Inventors: Vinod Kumar Daga, Craig Johnston, Ling Zheng
  • Patent number: 9268502
    Abstract: In one embodiment, a node coupled to one or more storage devices executes a storage input/output (I/O) stack having a volume layer. The volume layer manages volume metadata embodied as mappings from offsets of a logical unit (LUN) to extent keys associated with storage locations for extents on the one or more storage devices. Volume metadata is maintained as a dense tree metadata structure representing successive points in time. The dense tree metadata structure has multiple levels, wherein a top level of the dense tree metadata structure represents newer volume metadata changes and descending levels of the dense tree metadata structure represent older volume metadata changes. The node accesses a latest version of changes to the volume metadata by searching from the top level to the descending levels in the dense tree metadata structure.
    Type: Grant
    Filed: September 16, 2013
    Date of Patent: February 23, 2016
    Assignee: NetApp, Inc.
    Inventors: Ling Zheng, Blake H. Lewis, Kayuri H. Patel
  • Publication number: 20160048333
    Abstract: The embodiments described herein are directed to efficient merging of metadata managed by a volume layer of a storage input/output (I/O) stack executing on one or more nodes of a cluster. The metadata managed by the volume layer, i.e., the volume metadata, is illustratively organized as a multi-level dense tree metadata structure, wherein each level of the dense tree metadata structure (dense tree) includes volume metadata entries for storing the volume metadata. The volume metadata entries of an upper level of the dense tree metadata structure are merged with the volume metadata entries of a next lower level of the dense tree metadata structure when the upper level is full. The volume metadata entries of the merged levels are organized as metadata pages and stored as one or more files on the SSDs.
    Type: Application
    Filed: October 30, 2015
    Publication date: February 18, 2016
    Inventors: Ling Zheng, Blake H. Lewis
  • Patent number: 9256378
    Abstract: A method for sharing data blocks in a hierarchical file system in a storage server includes allocating a plurality of data blocks in the file system, and sharing data blocks in the file system, without using a persistent point-in-time image, to avoid duplication of data blocks. A method for identifying data blocks that can be shared includes computing a fingerprint for each of multiple data blocks to be written to a storage facility and storing the fingerprint with information identifying the data block in an entry in a set of metadata. The set of metadata is used to identify data blocks which are duplicates.
    Type: Grant
    Filed: May 23, 2013
    Date of Patent: February 9, 2016
    Assignee: NetApp, Inc.
    Inventors: Ling Zheng, Blake H. Lewis, Daniel W. Ting, Robert M. English, Stephen L. Manley
  • Publication number: 20160034489
    Abstract: A system can maintain multiple queues for deduplication requests of different priorities. The system can also designate priority of storage units. The scheduling priority of a deduplication request is based on the priority of the storage unit indicated in the deduplication request and a trigger for the deduplication request.
    Type: Application
    Filed: October 9, 2015
    Publication date: February 4, 2016
    Inventors: Blake Lewis, Ling Zheng, Craig Johnston, Vinod Daga
  • Publication number: 20160026652
    Abstract: In one embodiment, as new blocks of data are written to storage devices of a storage system, fingerprints are generated for those new blocks and inserted as entries into a top level (L0) of a dense tree data structure. When L0 is filled, the contents from L0 may be merged with level 1 (L1). After the initial merge, new fingerprints are added to L0 until L0 fills up again, which triggers a new merge. Duplicate fingerprints in L0 and L1 are identified which, in turn, indicates duplicate data blocks. A post-processing deduplication operation is then performed to remove duplicate data blocks corresponding to the duplicate fingerprints. In a different embodiment, as new fingerprint entries are loaded into L0, those new fingerprints may be compared with existing fingerprints loaded into L0 and/or other levels to facilitate inline deduplication to identify duplicate fingerprints and subsequently perform the deduplication operation.
    Type: Application
    Filed: July 24, 2014
    Publication date: January 28, 2016
    Inventor: Ling Zheng
  • Publication number: 20150370485
    Abstract: In one embodiment, a node coupled to one or more storage devices executes a storage input/output (I/O) stack having a volume layer, a persistence layer and an administration layer that interact to create a copy of a parent volume associated with a storage container on the one or more storage devices. A copy create start message is received at the persistence layer from the administration layer. The persistence layer ensures that dirty data for the parent volume is incorporated into the copy of the parent volume. New data for the parent volume received at the persistence layer during creation of the copy of the parent volume is prevented from incorporation into the copy of the parent volume. A reply to the copy create start message is sent from the persistence layer to the administration layer to initiate the creation of the copy of the parent volume at the volume layer.
    Type: Application
    Filed: August 28, 2015
    Publication date: December 24, 2015
    Inventors: Ling Zheng, Blake H. Lewis, Kayuri H. Patel
  • Patent number: 9201918
    Abstract: In one embodiment, a node of a cluster executing a storage input/output (I/O) stack having a volume layer, stores a multi-level dense tree metadata structure. Each level of the dense tree metadata structure includes volume metadata entries for storing volume metadata. One or more non-volatile logs (NVLogs) are updated. The one or more NVLogs including a volume layer log configured to record changes to the volume metadata, wherein volume metadata entries inserted into a top-level of the dense tree metadata structure are recorded in the volume layer log. The node writes volume metadata entries from the volume layer log to one or more storage devices to be stored as extents.
    Type: Grant
    Filed: November 19, 2013
    Date of Patent: December 1, 2015
    Assignee: NetApp, Inc.
    Inventors: Ling Zheng, Blake H. Lewis
  • Patent number: 9152684
    Abstract: In one embodiment, a node coupled to one or more storage devices executes a storage input/output (I/O) stack having a volume layer that manages volume metadata. The volume metadata is organized as one or more dense tree metadata structures having a top level residing in memory and lower levels residing on the one or more storage devices. The dense tree metadata structures include a first dense tree metadata structure associated with a parent volume and a second dense tree metadata structure associated with a copy of the parent volume. The top level of the first dense tree metadata structure may be copied to the second dense tree metadata structure. The lower levels of the first dense tree metadata structure are initially shared with the second dense tree metadata structure. The shared lower levels may eventually be split as the parent volume diverges from the copy of the parent volume.
    Type: Grant
    Filed: November 12, 2013
    Date of Patent: October 6, 2015
    Assignee: NetApp, Inc.
    Inventors: Ling Zheng, Blake H. Lewis, Kayuri H. Patel
  • Publication number: 20150185225
    Abstract: An optical analyte sensor and diabetes management system is provided. The sensor preferably includes a hydrogel matrix for receiving a sample containing an analyte at unknown concentration, a light emitter for emitting light at a stimulation frequency, a light receiver for receiving a fluorescence signal at a first isosbestic frequency, and at a second frequency, for measuring an intensity of the fluorescence signal and the first and second frequencies. A processor determines a concentration of the analyte based on the respective intensities.
    Type: Application
    Filed: July 31, 2014
    Publication date: July 2, 2015
    Applicant: BECTON, DICKINSON AND COMPANY
    Inventors: Paul Edney, Ling Zheng, James Petisce
  • Publication number: 20150142817
    Abstract: In one embodiment, a node of a cluster executing a storage input/output (I/O) stack having a volume layer, stores a multi-level dense tree metadata structure. Each level of the dense tree metadata structure includes volume metadata entries for storing volume metadata. One or more non-volatile logs (NVLogs) are updated. The one or more NVLogs including a volume layer log configured to record changes to the volume metadata, wherein volume metadata entries inserted into a top-level of the dense tree metadata structure are recorded in the volume layer log. The node writes volume metadata entries from the volume layer log to one or more storage devices to be stored as extents.
    Type: Application
    Filed: November 19, 2013
    Publication date: May 21, 2015
    Applicant: NetApp, Inc.
    Inventors: Ling Zheng, Blake H. Lewis
  • Patent number: 9037544
    Abstract: In one embodiment, snapshots and/or clones of storage objects are created and managed by a volume layer of a storage input/output (I/O) stack executing on one or more nodes of a cluster. Illustratively, the snapshots and clones may be represented as independent volumes, and embodied as respective read-only copies (snapshots) and read-write copies (clones) of a parent volume. Volume metadata is illustratively organized as one or more multi-level dense tree metadata structures, wherein each level of the dense tree metadata structure (dense tree) includes volume metadata entries for storing the metadata. Each snapshot/clone may be derived from a dense tree of the parent volume (parent dense tree). Portions of the parent dense tree may be shared with the snapshot/clone.
    Type: Grant
    Filed: January 23, 2014
    Date of Patent: May 19, 2015
    Assignee: NetApp, Inc.
    Inventors: Ling Zheng, Blake H. Lewis, Kayuri H. Patel
  • Publication number: 20150134879
    Abstract: In one embodiment, a node coupled to one or more storage devices executes a storage input/output (I/O) stack having a volume layer that manages volume metadata. The volume metadata is organized as one or more dense tree metadata structures having a top level residing in memory and lower levels residing on the one or more storage devices. The dense tree metadata structures include a first dense tree metadata structure associated with a parent volume and a second dense tree metadata structure associated with a copy of the parent volume. The top level of the first dense tree metadata structure may be copied to the second dense tree metadata structure. The lower levels of the first dense tree metadata structure are initially shared with the second dense tree metadata structure. The shared lower levels may eventually be split as the parent volume diverges from the copy of the parent volume.
    Type: Application
    Filed: November 12, 2013
    Publication date: May 14, 2015
    Applicant: NetApp, Inc.
    Inventors: Ling Zheng, Blake H. Lewis, Kayuri H. Patel
  • Publication number: 20150134616
    Abstract: In one embodiment, snapshots and/or clones of storage objects are created and managed by a volume layer of a storage input/output (I/O) stack executing on one or more nodes of a cluster. Illustratively, the snapshots and clones may be represented as independent volumes, and embodied as respective read-only copies (snapshots) and read-write copies (clones) of a parent volume. Volume metadata is illustratively organized as one or more multi-level dense tree metadata structures, wherein each level of the dense tree metadata structure (dense tree) includes volume metadata entries for storing the metadata. Each snapshot/clone may be derived from a dense tree of the parent volume (parent dense tree). Portions of the parent dense tree may be shared with the snapshot/clone.
    Type: Application
    Filed: January 23, 2014
    Publication date: May 14, 2015
    Applicant: NetApp, Inc.
    Inventors: Ling Zheng, Blake H. Lewis, Kayuri H. Patel
  • Patent number: 8996797
    Abstract: The embodiments described herein are directed to efficient logging and checkpointing of metadata managed by a volume layer of a storage input/output (I/O) stack executing on one or more nodes of a cluster. The metadata managed by the volume layer, i.e., the volume metadata, is illustratively organized as a multi-level dense tree metadata structure, wherein each level of the dense tree metadata structure (dense tree) includes volume metadata entries for storing the volume metadata. Each volume metadata entry may be a descriptor that embodies one of a plurality of types, including a data entry and an index entry, and a hole (i.e., absence of data) entry.
    Type: Grant
    Filed: January 22, 2014
    Date of Patent: March 31, 2015
    Assignee: NetApp, Inc.
    Inventors: Ling Zheng, Blake H. Lewis
  • Publication number: 20150081966
    Abstract: In one embodiment, a node coupled to one or more storage devices executes a storage input/output (I/O) stack having a volume layer. The volume layer manages volume metadata embodied as mappings from offsets of a logical unit (LUN) to extent keys associated with storage locations for extents on the one or more storage devices. Volume metadata is maintained as a dense tree metadata structure representing successive points in time. The dense tree metadata structure has multiple levels, wherein a top level of the dense tree metadata structure represents newer volume metadata changes and descending levels of the dense tree metadata structure represent older volume metadata changes. The node accesses a latest version of changes to the volume metadata by searching from the top level to the descending levels in the dense tree metadata structure.
    Type: Application
    Filed: September 16, 2013
    Publication date: March 19, 2015
    Applicant: NetApp, Inc.
    Inventors: Ling Zheng, Blake H. Lewis, Kayuri H. Patel
  • Patent number: 8971500
    Abstract: Prediction of a channel capacity is accomplished based on a TDR echo without explicitly estimating the topology of the line. The prediction is based on obtaining a measured TDR echo, determining a theoretical TDR echo for a plurality of loop lengths, estimating the equivalent TDR length based on an optimization, updating the equivalent TDR length and utilizing the updated TDR length to predict one or more of the upstream and downstream data rates.
    Type: Grant
    Filed: February 4, 2014
    Date of Patent: March 3, 2015
    Assignee: Broadcom Corporation
    Inventors: Ling Zheng, Michael A. Lund