Abstract: Method of defining a layout mapping function for a parity distributed RAID array including target objects, the layout mapping function defining the mapping of the stripe group-address space to the target-address space in the array and including a matrix defining a unit space across target objects, the matrix includes columns defining the objects and rows defining equally-offset sequential units on the objects, the method including: specifying P target objects, where P>1; b) specifying A target objects as spare space, where A<P and A?1; defining a sub-matrix of P? columns, where P?=P?A; defining a layout of stripe groups across the P? target objects in the sub-matrix, each stripe group comprising data units and parity units; adding A columns, representative of the A spare space target objects, to the sub-matrix to form a complete matrix defining the layout mapping function; and implementing the layout mapping function on the objects.

Abstract: There is provided a method of recovering configuration metadata from an erasure encoded RAID array. The RAID array includes raw data including a plurality of codewords encoded using Reed-Solomon encoding. The codewords include message data and checksum data, and the configuration metadata includes parameters relating to the layout of the RAID array. The method includes reading, from the RAID array, raw data including message data and checksum data. Then a set of linear equations are defined using the message data and checksum data. The linear equations are then solved and then, from the solved linear equations, one or more parameters relating to the layout of the RAID array are determined.

Abstract: 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.

Abstract: 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.

Abstract: Method of defining a layout mapping function for a parity distributed RAID array including target objects, the layout mapping function defining the mapping of the stripe group-address space to the target-address space in the array and including a matrix defining a unit space across target objects, the matrix includes columns defining the objects and rows defining equally-offset sequential units on the objects, the method including: specifying P target objects, where P>1; b) specifying A target objects as spare space, where A<P and A?1; defining a sub-matrix of P? columns, where P?=P?A; defining a layout of stripe groups across the P? target objects in the sub-matrix, each stripe group comprising data units and parity units; adding A columns, representative of the A spare space target objects, to the sub-matrix to form a complete matrix defining the layout mapping function; and implementing the layout mapping function on the objects.

Abstract: There is provided a method of recovering configuration metadata from an erasure encoded RAID array. The RAID array includes raw data including a plurality of codewords encoded using Reed-Solomon encoding. The codewords include message data and checksum data, and the configuration metadata includes parameters relating to the layout of the RAID array. The method includes reading, from the RAID array, raw data including message data and checksum data. Then a set of linear equations are defined using the message data and checksum data. The linear equations are then solved and then, from the solved linear equations, one or more parameters relating to the layout of the RAID array are determined.