Patent ID: 8694866

Claim:
A computer method of operating a controller of an array of storage nodes, the method comprising: receiving configuration data at the controller that indicates operating features of the array; and determining a parity code for operation of the array according to a permutation, wherein the configuration data specifies the array as comprising nodes defined by A=(a i,j ) with size r m ×k for some integers k,m, and wherein for T={v 0 , . . . , v k−1 } ⊂ Z r m a subset of vectors of size k, where for each v=(v 1 , . . . , v m ) ∈T, gcd(v 1 , . . . , v m ,r), where gcd is the greatest common divisor, such that for any l, 0≦l≦r−1, and v ∈T, the code values are determined by the permutation f v l :[0,r m −1]→[0,r m −1] by f v l (x)=x+lv.