| 摘要 |
The present invention provides a method and system for assigning data chunks to column parity sets in a dual-drive fault tolerant storage disk drive system having N disk drives, where N is a prime number. Each of the N disk drives are organized into N chunks such that the N disk drives are configured as one or more NxN array of chunks. The array has chunks arranged in N rows from row 1 to row N and in N columns from column 1 to column N. Each row includes a plurality of data chunks for storing data, a column parity chunk for storing a column parity set, and a row parity chunk for storing a row parity set. These data chunks are assigned in a predetermined order. The data chunks in each row are assigned to the row parity set. Each column parity set is associated with a set of data chunks in the array, wherein row m is associated with column parity set Qm where m is an integer that ranges from 1 to N. For row 1 of a selected NxN array, a first data chunk is assigned to a column parity set Qi wherein i is an integer determined by rounding down (N/2). For each of the remaining data chunks in row 1, each data chunk is assigned to a column parity set Qj, wherein j is an integer one less than the column parity set for the preceding data chunk and wherein j wraps to N when j is equal to 0. For each of the remaining rows 2 to N of the selected array, a first logical data chunk is assigned to a column parity set Qk, wherein k is one greater than the column parity set for the first logical data chunk in a preceding row and wherein k wraps to 1 when k is equal to (N+1). For each of the remaining data chunks in rows 2 to N, each data chunk is assigned to a column parity set Qn, wherein n is an integer one less than a column parity set for the preceding data chunk and wherein n wraps to N when n is equal to 0.
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