US 7,743,308 B2 · Method and system for wire-speed parity generation and data rebuild in RAID systems

Abstract

A method and system for generating parity symbols and rebuilding data symbols in a RAID system. The method includes receiving a command to generate a desired parity or data symbol using an XOR relationship between some of a plurality of parity and data symbols. A symbol of the plurality of parity and data symbols is input to an XOR accumulator, the symbol being included in the XOR relationship. Additional symbols of the plurality of parity and data symbols are input to the XOR accumulator. Each time that an additional symbol is input and is included in the XOR relationship, an XOR operation is performed between the symbol in the XOR accumulator and the additional symbol, thus obtaining a resulting symbol that replaces the previous symbol in the XOR accumulator. After every symbol included in the XOR relationship has undergone an XOR operation, the symbol in the XOR accumulator is output as the desired parity or data symbol.

Claims19

Dependent claims

A method for generating parity symbols and for rebuilding data symbols in both RAID5 and RAID6 systems, comprising:

receiving an XOR command packet, the XOR command packet including a command to generate a desired P parity in a RAID5 system or a desired P and Q parity in a RAID6 system or to rebuild a missing data symbol using an XOR relationship between some of a plurality of parity and data symbols;
inputting a symbol of the plurality of parity and data symbols to an XOR accumulator hardware, the symbol being included in the XOR relationship, the XOR relationship being defined in a symbol routing table in the XOR accumulator hardware;
inputting additional symbols of the plurality of parity and data symbols to the XOR accumulator hardware;
each time that an additional symbol is input and is included in the XOR relationship, performing an XOR operation between the symbol in the XOR accumulator hardware and the additional symbol to obtain a resulting symbol that replaces the previous symbol in the XOR accumulator hardware;
and
after every symbol included in the XOR relationship has undergone an XOR operation, outputting the symbol in the XOR accumulator hardware as the desired parity or data symbol,
wherein said method for generating parity symbols and rebuilding data symbols in RAID5 and RAID6 systems occurs at wire speed.

4 more elements

An XOR engine hardware for generating a plurality of P parity symbols and P and Q parity symbols and for rebuilding a plurality of data symbols, the plurality of symbols stored on a plurality of disks in a RAID system, the XOR engine hardware comprising:

a cache data buffer manager that manages the input and output of the plurality of symbols to and from the XOR engine hardware;
a data integrity field engine that verifies whether each of the plurality of symbols input from the cache data buffer manager or output to the cache data buffer manager is in a correct format;
and
a plurality of multi-accumulators that each input the plurality of symbols received by the data integrity field engine from the cache data buffer manager and output a plurality of results from a plurality of XOR operations performed on the plurality of symbols, the plurality of results being output to the data integrity field engine, the plurality of results including P parity symbols for RAID5 systems, P and Q parity symbols for RAID6 systems, and rebuilt data symbols, wherein each of the plurality of multi-accumulators further comprises a symbol routing table that includes a relationship between a portion of the plurality of symbols and a plurality of XOR accumulators for performing XOR operations on the portion of the plurality of symbols according to the relationship in the symbol routing table.

1 more element

Dependencies are inferred from the claim text.

Method and system for wire-speed parity generation and data rebuild in RAID systems

Life of this patent

Method and system for wire-speed parity generation and data rebuild in RAID systems

Life of this patent

Abstract

Claims19