Shifting an encoded data slice subset for smart rebuilding
A method includes generating a second encoded data slice of a second subset of encoded data slices of a set of encoded data slices, where the second subset of encoded data slices is not currently stored in a set of storage units of the storage network, where the set of encoded data slices include a first subset of encoded data slices that is stored in the set of storage units and includes at least a decode threshold number of encoded data slices of the set of encoded data slices, and where a first encoded data slice of the first subset requires rebuilding. The method further includes sending the second encoded data slice to the set of storage units for storage therein, where when the second encoded data slice is stored, the second encoded data slice no longer included in the second subset of encoded data slices.
1 . A method for execution by one or more computing devices within a storage network, the method comprises:
generating a second encoded data slice of a second subset of encoded data slices of a set of encoded data slices, wherein the second subset of encoded data slices is not currently stored in a set of storage units of the storage network, wherein the set of encoded data slices include a first subset of encoded data slices that is stored in the set of storage units and includes at least a decode threshold number of encoded data slices of the set of encoded data slices, and wherein a first encoded data slice of the first subset requires rebuilding; and
sending the second encoded data slice to the set of storage units for storage therein, wherein when the second encoded data slice is stored, the second encoded data slice is no longer included in the second subset of encoded data slices.
2 . The method of claim 1 further comprises:
identifying the second encoded data slice based on identifying a storage unit of the set of storage units that is mapped to store a respective encoded data slice of the second subset of encoded data slices.
3 . The method of claim 2 , wherein the identifying the storage unit is based on determining the storage unit has been restored within a time period.
4 . The method of claim 2 , wherein the identifying the storage unit is based on determining the storage unit has been upgraded within a time period.
5 . The method of claim 2 , wherein the identifying the storage unit is based on determining the storage unit has not been used previously to store an encoded data slice of the set of encoded data slices.
6 . The method of claim 2 , wherein the identifying the storage unit is based on determining the storage unit is within a performance range of other storage units in the set of storage units.
7 . The method of claim 2 , wherein the identifying the storage unit is based on determining the storage unit has not been used previously for storing any of the first subset of encoded data slices of the set of encoded data slices.
8 . The method of claim 1 further comprises:
error encoding a data segment of data to produce the first subset of encoded data slices; and
sending the first subset of encoded data slices to the set of storage units for storage therein.
9 . The method of claim 8 , wherein the error encoding the data segment is in accordance with error encoding parameters, and wherein the error encoding parameters include the decode threshold number and a pillar width number.
10 . The method of claim 9 , wherein the set of encoded data slices includes the pillar width number.
11 . The method of claim 10 , wherein a number of the second subset of encoded data slices comprises:
the pillar width number minus a number of the first subset of encoded data slices.
12 . The method of claim 1 , wherein the generating the second encoded data slice comprises:
retrieving the decode threshold number of encoded data slices of the first subset of encoded data slices;
error decoding the decode threshold number of encoded data slices to reconstruct a data segment associated with the set of encoded data slices; and
error encoding at least a portion of the reconstructed data segment to produce the second encoded data slice.
13 . The method of claim 12 , wherein the error encoding comprises:
arranging the reconstructed data segment into a data matrix;
obtaining a row of an encoding matrix that corresponds to the second encoded data slice of the set of encoded data slices; and
matrix multiplying the selected row of the encoding matrix with the data matrix to produce the second encoded data slice.
14 . The method of claim 13 further comprises:
identifying a third encoded data slice of the second subset of encoded data slices; and
generating the third encoded data slice from the first subset of encoded data slices.
15 . The method of claim 14 , wherein the generating the third encoded data slice comprises:
error encoding the reconstructed data segment to produce the third encoded data slice.
16 . The method of claim 15 , wherein the error encoding the reconstructed data segment to produce the third encoded data slice comprises:
obtaining a second row of the encoding matrix that corresponds to the third encoded data slice of the set of encoded data slices; and
matrix multiplying the second row of the encoding matrix with the data matrix to produce the third encoded data slice.
17 . The method of claim 1 , wherein determining the first subset of encoded data slices comprises:
receiving, from storage units of the set of storage units, favorable listing responses to a listing request for the first subset of encoded data slices, wherein a first favorable listing response of the favorable listing responses indicates a corresponding storage unit is storing a corresponding encoded data slice of the first subset of encoded data slices.
18 . The method of claim 17 further comprises:
determining an additional encoded data slice of the set of encoded data slices is stored in the set of storage units, wherein the additional encoded data slice was not included in the favorable listing responses; and
updating the first subset of encoded data slices based on the additional encoded data slice.
19 . The method of claim 1 , wherein determining a number of encoded data slices within the first subset of encoded data slices comprises:
obtaining the number by performing a lookup in a lookup table.
20 . A computing device of a storage network, the computing device comprises:
memory;
an interface; and
at least one processing module operably coupled to the memory and the interface, wherein the at least one processing module is operable to:
generate a second encoded data slice of a second subset of encoded data slices of a set of encoded data slices, wherein the second subset of encoded data slices is not currently stored in a set of storage units of the storage network, wherein the set of encoded data slices include a first subset of encoded data slices that is stored in the set of storage units and includes at least a decode threshold number of encoded data slices of the set of encoded data slices, and wherein a first encoded data slice of the first subset requires rebuilding; and
send, via the interface, the second encoded data slice to the set of storage units for storage therein, wherein when the second encoded data slice is stored, the second encoded data slice is no longer included in the second subset of encoded data slices.