Accelerated data recovery using a repeating stripe group arrangement

摘要

A method of defining a layout mapping function for a parity distributed RAID array including a plurality of target objects, the layout mapping function defining the mapping of the group-address space to the target-address space in the array and including a matrix defining a unit space across a plurality of target objects, the matrix Includes columns defining the target objects and rows defining equally-offset sequential units on the target objects, the method including: a) defining, on a computing apparatus, a layout of stripe groups across the target objects by defining a pattern including a plurality of stripe groups into a predetermined pattern and repeating the pattern across the matrix, each stripe group including a plurality of data units and a plurality of parity units; and b) implementing, on a computing apparatus, the layout on the target objects of the RAID array.

主权项

1. A method comprising:
arranging a plurality of storage devices in communication with a control circuit to form a combined memory space configured for storage of stripe groups across multiple ones of the plurality of storage devices, each stripe group comprising a distributed data set having a plurality of user data units and at least one parity unit; using the control circuit a data structure comprising a two dimensional map of the combined memory space with each of the storage devices represented along a first dimension of the two dimensional map and equally-offset sequential units of storage capacity of the plurality of storage devices represented along a second dimension of the two dimensional map, each of the equally-offset sequential units of storage capacity substantially equal in size to a selected one of the plurality of user data units or at least one parity unit in each stripe group; defining, by the control circuit, a stripe group set comprising a plurality of sequential stripe coups arranged into a W x R pattern across the storage devices with W comprising a plural number width parameter representing a total number of the plurality of sequential stripe groups arranged across a common set of the storage devices in successive sequential units of storage capacity in the first dimension and R comprising a plural number repeating parameter representing a total number of different sets of the storage devices across which the plurality of sequential stripe groups are stored in the second dimension; populating, by the control circuit, the data structure by repeating the W×R pattern within the two dimensional map in both the first dimension and the second dimension to define target locations for host data; and using the control circuit to arrange data received from a host into host data stripe groups and to direct storage of the host data stripe groups to the storage devices in accordance with the populated data structure.