Netapp, Inc.

Richard Jernigan

Jonathan Curley

Devang Kundanlal Shah

Srishylam Simharajan

Xin Wang

Adam F Ciapponi

Bill Zumach

Keith Bare

Richard Chow

Brad Lisson

Dave Rose

Ram Kesavan

Subramanian Natarajan

Bryan Schmersal

Garrett Arthur Kajmowicz

Robert W Hyer

Approaches to data flow bottleneck management using caching mechanisms in a distributed storage environment are disclosed. A read request is received by a first data storage node having a first set of interface module(s), a first set of data management module(s), a first redirection layer, and a first set of data storage devices. The read request has a corresponding file to be read. The first redirection layer is checked for an entry corresponding to the file. The read request is routed based on a file characteristic corresponding to the read request if there is no corresponding entry in the first redirection layer or to a second data storage node based on the entry in the first redirection layer. Potential bottleneck conditions are monitored on the first node. A redirection layer entry in the first redirection layer is generated in response to determining that a bottleneck condition exists.

Bottleneck management techniques using non-disruptive file movement mechanisms in distributed storage environments

Methods, non-transitory machine readable media, and computing devices that ensure correctness of file system analytics are disclosed. With this technology, a first generation number for a volume is incremented in response to a modification of a rule set that defines properties of objects of a file system associated with the volume. A determination is made when a second generation number in a first inode for a first one of the objects matches the first generation number. The first inode is identified based on a traversal of a directory tree associated with the file system. The modified rule set is applied to the properties for the first one of the objects to obtain values, when the second generation number fails to match the first generation number. Analytics data is output after the traversal has completed. The analytics data is generated in response to a query and is based on the values.

Methods for ensuring correctness of file system analytics and devices thereof

Methods, non-transitory machine readable media, and computing devices that provide more efficient hierarchical propagation in tree structures are disclosed. With this technology, a first delta record for a first interior node is created optionally in an atomic transaction along with updating a first tally record for a leaf node based on a first value. The transaction is in response to an action associated with the leaf node and the first interior node is a parent of the leaf node in a hierarchical tree. A timer associated with the first delta record is then set. A second value is updated in a second tally record for the first interior node based on the first value, when the timer has expired. Accordingly, this technology advantageously maintains recursive properties or values throughout a hierarchical tree continually, with reduced cost, even in a distributed network and in hierarchical trees with large numbers of nodes.

Methods for hierarchical propagation in tree structures and devices thereof

A method, non-transitory computer readable medium, and device that replicates data and provides instantaneous access to data includes receiving in a destination volume one or more named data extents and one or more references to the one or more named data extents associated with a file in parallel from a source volume. A determination is made to check whether the one or more references arrive before the one or more named data extents arrive. Each of the received one or more references which are determined to have arrived prior to the one or more data extents is allocated as absent by the storage management computing device. An instantaneous access to the file is provided during the allocation.

Methods for replicating data and enabling instantaneous access to data and devices thereof

Systems and methods which provide an absent allocation technique with respect to absent data of a data structure for which data migration in a time-displaced data migration operation has not completed are disclosed. Through use of absent allocated data block states of an absent allocation technique of embodiments, dependency between source and destination data stores may be broken. An absent allocated data block state of embodiments stored within the data structure provides a suggestive indication that data of a data block of a data structure is absent from the data structure. A corresponding absent allocated data block state of embodiments stored external to the data structure provides a determinative indication that the data of the data block of the data structure is absent from the data structure. The absent data block determinative indictor of embodiments is updated as data continues to be migrated.

Allocation of absent data within filesystems

Methods and a processing system directed to a file system checker are described. A file system checker performs file system validation by validating a file system's nodes. Each node is associated with two kinds of data: metadata and referenced data. A file system checker may validate one node at a time or a group of nodes contemporaneously (e.g., in parallel). The file system checker uses a dual phase procedure. The first phase includes validating metadata. The second phase includes validating, as appropriate, node type or link count. Dual phase file system checking allows validation of a node without validating referenced data associated with downstream nodes. Where validation of a given node requires validating a downstream node, performing a first phase test on the downstream node is sufficient to validate the given node. Upon completion, the given node may be unlocked for access by external devices and users.

Dual-phase file system checker

The present invention overcomes the disadvantages of the prior art by providing a technique that stripes data containers across volumes of a striped volume set (SVS) using one of a plurality of different data placement patterns to thereby reduce the possibility of hotspots arising due to each data container using the same data placement pattern within the SVS. The technique is illustratively implemented by calculating a first index value, an intermediate index value and calculating a hash value of an inode associated with a data container to be accessed within the SVS. A final index value is calculated by multiplying the intermediate index value by the hash value, modulo the number of volumes of the SVS. Further, a Locate( ) function may be used to compute the location of data container content in the SVS to which a data access request is directed to ensure consistency of such content.

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Sewickley, PA, United States of America

Richard Jernigan