Patent Document ID: 8037391
Application ID: 12471289
Patent Status: 1

Claim One:
1. A computer-implemented method for computing erasure codes for a redundant array of independent disks (RAID), the method comprising: storing user data associated with a RAID stripe that is defined by a data block common to each disk in the redundant array, wherein, for each byte offset within the data block, user data associated with only N−2 disks is stored, N being the number of disks in the redundant array; for each byte offset within the data block, computing a first erasure code by accumulating a plurality of values generated by performing, across each disk in the redundant array, a first exclusive-or operation based on the byte offset within the data block; for each byte offset within the data block, computing a second erasure code by accumulating a plurality of values generated by performing, across each disk in the redundant array, a second exclusive-or operation based on a look-up table value, wherein, each disk in the redundant array is associated with a respective disk drive number, and the respective disk drive number is input as an index to the look-up table to generate the look-up table value; and for each byte offset within the data block, storing the first erasure code and the second erasure code along with the user data associated with the N−2 disks.