Pure Storage, Inc.

International Business Machines Corporation

Thomas Darrel Cocagne

Jason K Resch

Greg R Dhuse

Ilya Volvovski

Ravi V Khadiwala

Wesley B Leggette

Michael Colin Storm

Gary W Grube

Yogesh Ramesh Vedpathak

Manish Motwani

Timothy W Markison

Bruno Hennig Cabral

Andrew D Baptist

Thomas Franklin Shirley, Jr

Bart Richard Cilfone

Ethan S Wozniak

Joseph M Kaczmarek

Asimuddin Kazi

Sebastien Vas

Andrew George Peake

Sanjaya Kumar

Bart Richard Clifone

Anthony J Baldocchi

A storage network operates by: storing at least one data object in the storage network as encoded data slices that are dispersed error encoded, the encoded data slices including locally decodable code segments; detecting at least one storage error associated with storage of at least one of the encoded data slices in the storage network; and recovering and at least one of the encoded data slices utilizing the locally decodable code segments.

Recovering a data segment using locally decodable code segments

A computing device includes an interface for communicating with a storage network and is configured to determine a performance level for each set of storage units of a plurality of sets storage units in the storage network, where the performance level includes a number of errors detected during a period of time T. The computing device is further configured to update performance information for the plurality of sets storage units to produce updated performance information for the plurality of sets storage units and determine which sets of storage units of the plurality of sets storage units meet a minimum performance level. The computing device is configured to receive a set of read requests for a set of encoded data slices stored on the plurality of sets storage units and transmit a threshold number of read requests of the set of read requests to a set of storage units that meet the minimum performance level.

Performance based access in a storage network

A processing system of a storage network operates by: sending, to at least one storage unit of the storage network, at least one read request corresponding to at least a read threshold number of a set of encoded data slices to be retrieved, wherein the set of encoded data slices correspond to data, wherein the data is coded in accordance with dispersed error coding parameters that include a write threshold number and the read threshold number, wherein the write threshold number is a number of encoded data slices in the set of encoded data slices and wherein the read threshold number is a number of the set of encoded data slices that is required to decode the data; receiving, via the at least one processing circuit and from the at least one storage unit, a first subset of the set of encoded data slices, wherein the first subset is missing at least one missing encoded data slice that was not received from the at least one storage unit in response to the at least one read request and wherein a number of encoded data slices in the first subset is less than the read threshold number; generating, via the at least one processing circuit, at least one rebuilt encoded data slice corresponding to the at least one missing encoded data slice utilizing locally decodable redundancy data, wherein the locally decodable redundancy data generated from a second subset of the set of encoded data slices that includes the at least one missing encoded data slice; and recovering, via the at least one processing circuit, the data based on the at least one rebuilt encoded data slice and the first subset.

Rebuilding missing data in a storage network via locally decodable redundancy data

A method for execution by one or more computing devices of a storage network includes identifying a storage unit of a set of storage units for testing, where a data segment of data is error encoded into a set of encoded data slices that is stored in the set of storage units. The method further includes determining whether a threshold number of favorably performing other storage units of the set of storage units will be available during the testing. When the threshold number of favorably performing other storage units will be available, the method further includes initiating the testing of the storage unit and setting a status of the storage unit to unavailable. When the testing has been completed, the method further includes updating the status of the storage unit to available. The method further includes generating a testing report regarding the testing of the storage unit.

Testing a storage unit in a storage network

A processing system of a storage network operates by: generating a request for a plurality of system registry files; receiving the plurality of system registry files via a network; generating a verification indicator based on an integrity check of the plurality of system registry files versus system registry integrity data corresponding to the plurality of system registry files; and storing the system registry files in memory when the verification indicator indicates that verification was successful.

Storage network with system registry file verification

A processing system of a storage network operates by: sending, to at least one storage unit of the storage network, at least one read request corresponding to at least a read threshold number of a set of encoded data slices to be retrieved, wherein the set of encoded data slices correspond to a data segment, wherein the data segment is coded in accordance with dispersed error coding parameters that include a write threshold number and the read threshold number, wherein the write threshold number is a number of encoded data slices in the set of encoded data slices and wherein the read threshold number is a number of the set of slices that is required to decode the data segment; receiving, via the at least one processing circuit and from the at least one storage unit, a first subset of encoded data slices of the set of encoded data slices, wherein the first subset of encoded data slices is missing at least one missing encoded data slice that was not received from the at least one storage unit in response to the at least one read request and wherein the number of encoded data slices in the first subset of the encoded data slices is less than the read threshold number; generating, via the at least one processing circuit, at least one rebuilt encoded data slice corresponding to the at least one missing encoded data slice utilizing locally decodable redundancy data, wherein the locally decodable redundancy data generated from a second subset of the set of encoded data slices that includes the at least one missing encoded data slice; and recovering, via the at least one processing circuit, the data segment based on the at least one rebuilt encoded data slice and the first subset of encoded data slices.

Recovering missing data in a storage network via locally decodable redundancy data

A network storage system operates by: sending, to at least one storage unit of a storage network, at least one read request corresponding to at least a read threshold number of a set of encoded data slices to be retrieved, wherein the set of encoded data slices correspond to a data segment, wherein the data segment is codable in accordance with dispersed error coding parameters that include a write threshold number and the read threshold number, wherein the write threshold number is a number of encoded data slices in the set of encoded data slices and wherein the read threshold number is a number of the set of slices that is required to decode the data segment; receiving from the at least one storage unit, a first subset of encoded data slices of the set of encoded data slices, wherein the first subset of encoded data slices is missing at least one missing encoded data slice from the number of the set of slices that is required to decode the data segment and that was not received from the at least one storage unit in response to the at least one read request; generating at least one rebuilt encoded data slice corresponding to the at least one missing encoded data slice utilizing locally decodable redundancy data, wherein the locally decodable redundancy data includes a plurality of local redundancy slices generated from a second subset of the set of encoded data slices that includes the at least one missing encoded data slice; and recovering the data segment based on the at least one rebuilt encoded data slice and the first subset of encoded data slices.

Utilizing locally decodable redundancy data in a vast storage network

A storage network operates by storing at least one data object in the SN as encoded data slices that are dispersed error encoded; detecting at least one storage error associated with storage of at least one of the encoded data slices in the storage network; and rebuilding the at least one of the encoded data slices associated with the storage error utilizing locally decodable code segments.

Rebuilding of encoded data slices using locally decodable code segments

A method for updating software of storage units of a set of storage units in a storage network. In an embodiment, each storage unit of the set of storage units determines a data slice storage status for data slices stored in the storage unit (e.g., by monitoring rebuilding messages relating to the data slices). A processing module of the storage network obtains the data slice storage status of the storage units of the set of storage units and determines whether to perform a software update to software of the storage units of the set of storage units. Determining whether to perform the software update includes determining, based on the data slice storage status of the storage units, whether a threshold number of storage units are associated with a favorable data slice storage status. In response to determining that a threshold number of storage units are associated with a favorable data slice storage status, the processing module indicates to perform the software update.

Updating the configuration of storage units of a storage network

In various embodiments, a method is presented for execution by a processing circuit of a storage network device that includes a processor. The method comprises: receiving, via the processing circuit, a first subset of encoded data slices of a set of encoded data slices corresponding to a data segment; identifying, via the processing circuit, at least one missing encoded data slice of the first subset of slices that is required to decode the data segment; generating, via the processing circuit, at least one rebuilt encoded data slice corresponding to the at least one missing encoded data slice utilizing locally decodable redundancy data; and recovering, via the processing circuit, the data segment based on the at least one rebuilt encoded data slice and the first subset of encoded data slices.

Rebuilding data via locally decodable redundancy in a vast storage network

A method for execution by a dispersed storage and task (DST) execution unit includes receiving system registry integrity data via a network that corresponds to a plurality of system registry files, a request for a subset of the plurality of system registry files is generated for transmission to a dispersed storage network (DSN) unit via the network. The subset of system registry files are received from the DSN unit via the network. Integrity check data is generated based on the received subset of the plurality of system registry files and the system registry integrity data, where the integrity check data includes a verification indicator. The system registry files are stored in memory when the verification indicator indicates that verification was successful.

Verifying system registry files in a storage network

Methods and apparatus for selecting data access resources in a distributed storage network (DSN) are disclosed. In various embodiments, a processing module(s) receives a data access request including a data identifier. Addressing information is determined for the data access request. In addition, the processing module obtains DSN configuration information associated with a plurality of access resources that interface with DSN memory. Ranked scoring information is determined for the plurality of access resources based, at least in part, on the DSN configuration information and the addressing information. In an example, a distributed agreement protocol module is utilized to calculate the ranked scoring information as a processing capacity of a respective access resource divided by a negative log of a normalized deterministic function value based on the addressing information and an identifier. The ranked scoring information is then utilized to select an access resource for processing of the data access request.

Selection of access resources in a distributed storage network

A computing device includes an interface configured to interface and communicate with a storage network, a memory that stores operational instructions, and processing circuitry operably coupled to the interface and to the memory. The processing circuitry is configured to execute the operational instructions to perform various operations and functions. The computing device determines to execute maintenance operations on a set of memory devices, selects a subset of the set of memory devices for the maintenance operations and initiates execution of the maintenance operations on the subset of memory devices. When a read request is received for a set of encoded data slices (EDSs) associated with the subset of memory devices, the computing device is configured to identify a threshold number of EDSs not associated with the subset of memory devices, issue read requests to storage units storing the threshold number of EDSs and determine whether the subset of memory devices have completed executing the maintenance operations.

Managed data slice maintenance in a distributed storage system

A method begins by a processing module of a dispersed storage network (DSN) determining a fault domain for a portion of the DSN and generating a local redundancy for the fault domain. The method continues with the processing module identifying storage locations available for storing the first local redundancy, selecting storage locations for storing the first local redundancy and continues with the processing module facilitating storage of the local redundancy in the storage locations. Upon detecting a storage failure in the DSN, the method continues with the processing module determining whether the storage failure is associated with the fault domain and in response determining whether the first local redundancy is associated with the first fault domain. In response to determining that the local redundancy is associated with the first fault domain the method continues with the processing module recovering the local redundancy and correcting the storage failure.

Reliably recovering stored data in a dispersed storage network

A computing device includes an interface configured to interface and communicate with a dispersed storage network (DSN), a memory that stores operational instructions, and processing circuitry operably coupled to the interface and to the memory. The processing circuitry is configured to execute the operational instructions to perform various operations and functions. The computing device detects a total number of errors that is associated with a set of memory devices of one or more sets of storage units (SUs) within a DSN that distributedly store a set of encoded data slices (EDSs). When the total number of errors compares unfavorably to a priority error threshold level, the computing device indicates that a minimum number of error-free EDSs are available of the set of EDSs. The computing device also selects a mechanism for data retention process from a plurality of mechanisms for data retention process and executes it.

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Elk Grove Village, IL, United States of America

Thomas Darrel Cocagne