Likelihood based rebuilding of missing encoded data slices

摘要

A method begins by a processing module of a dispersed storage network (DSN) detecting a likelihood of having a missing encoded data slice based on local physical to DSN address mapping information. When the likelihood of having the missing encoded data slice exists, the method continues with the processing module sending a query regarding the missing encoded data slice to another storage unit of the DSN and receiving a response to the query from the other storage unit. When the response includes identity of a related encoded data slice of a set of encoded data slices, the method continues with the processing module commencing execution of a rebuilding function to generate a new encoded data slice to replace the missing encoded data slice.

主权项

1. A method for execution by a storage unit of a dispersed storage network (DSN), the method comprises:
detecting a likelihood of the storage unit having a missing encoded data slice based on local physical-to-DSN address mapping information by interpreting the local physical-to-DSN address mapping information to determine that a sub-range of DSN addresses is not affiliated with a particular memory device of the storage unit; and when the likelihood of having the missing encoded data slice exists:
sending a query regarding the missing encoded data slice to another storage unit of the DSN;receiving a response to the query from the other storage unit; andwhen the response includes identity of a related encoded data slice of a set of encoded data slices, commencing execution of a rebuilding function to generate a new encoded data slice to replace the missing encoded data slice, wherein a data segment of a data object is encoded into the set of encoded data slices, wherein a threshold number of encoded data slices of the set of encoded data slices is required to recover the data segment, wherein the threshold number is less than a number of encoded data slices in the set of encoded data slices, wherein the other storage unit stores the related encoded data slice, wherein the storage unit has been assigned to store a second encoded data slice of the set of encoded data slices, and wherein the second encoded data slice corresponds to the missing encoded data slice.