RAID-6 computation system and method

A computer-readable medium including instructions that, when executed by a processing unit, cause the processing unit to compute erasure codes for a redundant array of independent disks (RAID), by performing the steps of:

• 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, and wherein a sliver comprises a set of S bytes per disk within the RAID stripe at a common sliver offset within each disk;
• calculating a sliver offset for accessing an assigned sliver based on a thread identification number;
• for each byte offset within the assigned sliver, 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 assigned sliver, 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;
• and
• for each byte offset within the assigned sliver, storing the first erasure code and the second erasure code along with the user data associated with the N−2 disks.

A computer system, comprising:

• a central-processing unit;
• a multi-threaded processing unit coupled to the central-processing unit;
• a system memory coupled to the central processing unit and the multi-threaded processing unit;
• and
• a redundant array of independent disks (RAID) coupled to the central processing unit, multi-threaded processing unit, and the system memory,
• wherein the multi-threaded processing unit is configured to compute erasure codes for the redundant array by performing the steps of:
• 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, and wherein a sliver comprises a set of S bytes per disk within the RAID stripe at a common sliver offset within each disk;
• calculating a sliver offset for accessing an assigned sliver based on a thread identification number;
• for each byte offset within the assigned sliver, 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 assigned sliver, 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;
• and
• for each byte offset within the assigned sliver, storing the first erasure code and the second erasure code along with the user data associated with the N−2 disks.