FIELD: physics.
SUBSTANCE: invention relates to a method of arranging data in a RAID array for balanced load distribution during array recovery. Method comprises steps of creating a new RAID array using a procedure for generating a stripe map; number of free disks N, length of current stripe L and the length of the stripe arrangement map R is passed at the input of the procedure for generate a stripe map and based on the obtained data, a stripe map consisting of R concatenated permutations of the set {1, …, N} is formed; matrix of combinations M of size N×N is initialized, during which all its elements are assigned values of 0, the current stripe is initialized with an empty list; permutation is generated in the stripe map by calling the generate permutation procedure with the following input parameters: current value of combination matrix M, list of occupied disks in current stripe, length of current stripe L, number of disks in RAID array N; to generate one permutation based on input parameters, auxiliary structures are initialized, namely: list of free disks is initialized with numbers from 1 to N, list of disks in current permutation is initialized with empty list; iterative selection of a disk which is contained in the list of free disks, but is not contained in the list of occupied disks in the current stripe, using the search for the minimum sum of the elements of the combination matrix corresponding to the disk, and occupied disks in the current stripe; adding a disc to a list of occupied discs in the current stripe and to the end of the list of discs in the current permutation; once the length of the list of occupied disks in the current stripe has reached the length of the current stripe L, updating the combination matrix and assigning the list of occupied disks in the current stripe to an empty list value; procedure for generation of a permutation in a stripe arrangement map is repeated until the number of permutations reaches R.
EFFECT: faster recovery of a RAID array due to a data arrangement scheme which ensures uniform distribution of the read load across all disks during recovery of the array.
1 cl, 9 dwg
