US 2018/0322009 A1 · MULTI-STAGE SLICE RECOVERY IN A DISPERSED STORAGE NETWORK

Abstract

A method and computing device for use in a dispersed storage network (DSN) to recover corrupt encoded data slices. In response to a request to storage units of the DSN for encoded data slices corresponding to a data segment, the computing device of a receives at least a decode threshold number of encoded data slices and at least one integrity error message that provides an indication of a corrupt encoded data slice, such that less than a decoded threshold number of valid slices is received. Utilizing at least one correction approach involving stored integrity data, the computing device then corrects the corrupt slice(s) to produce a decode threshold number of encoded data slices in order to decode the corresponding data segment. A variety of correction approaches may be employed, including a multi-stage approach that utilizes data from both valid and invalid slices.

Claims16

Dependent claims

A method for execution by one or more processing modules of one or more computing devices of a dispersed storage network (DSN), the method comprises:

in response to a request for encoded data slices of an encoded portion of a corresponding data segment, receiving at least a decode threshold number of encoded data slices from a set of storage units of the DSN in which the encoded data slices are stored, the encoded data slices including at least one encoded data slice identified as corrupt by a storage unit of the set of storage units (“at least one corrupt encoded data slice”) and less than a decoded threshold number of encoded data slices identified as valid by the set of storage units;
applying stored integrity information corresponding to the at least one encoded data slice identified as corrupt to determine if the at least one encoded data slice is valid;
and
in response to determining that the at least one encoded data slice is not valid, correcting the at least one corrupt encoded data slice utilizing stored additional integrity information and at least one correction approach to produce the decode threshold number of encoded data slices.

1 more element

A computing device of a group of computing devices of a dispersed storage network (DSN), the computing device comprises:

an interface;
a local memory;
and
a processing module operably coupled to the interface and the local memory, wherein the processing module is configured to:
transmit to a set of storage units of the DSN, via the interface, a request for encoded data slices, wherein each of the encoded data slices is an encoded portion of a corresponding data segment;
receive, via the interface, at least a decode threshold number of requested encoded data slices from the set of storage units of the DSN, the encoded data slices including at least one encoded data slice identified as corrupt by a storage unit of the set of storage units (“at least one corrupt encoded data slice”) and less than a decoded threshold number of encoded data slices identified as valid by the set of storage units;
apply stored integrity information corresponding to the at least one corrupt encoded data slice to determine if the at least one corrupt encoded data slice is instead valid;
and
in response to determining that the at least one corrupt encoded data slice is not valid, correct the at least one corrupt encoded data slice utilizing stored additional integrity information and at least one correction approach to produce the decode threshold number of encoded data slices.

6 more elements

Dependencies are inferred from the claim text.

Multi-stage slice recovery in a dispersed storage network

Life of this patent

Multi-stage slice recovery in a dispersed storage network

Life of this patent

Abstract

Claims16