Back to results
US 8,898,380 B2Granted
Memory efficient check of raid information
AssigneeLSI Corporation
InventorWilliam Patrick Delaney
Life of this patent
Estimating the term…
Abstract
Disclosed is a RAID data checking system. I/O controllers to read data RAID data from the storage devices and transfer that data to virtual memory address ranges. The P+Q checking function receives the data sent to the virtual memory address ranges. However, instead of storing the incoming data, the P+Q checking function updates intermediate values of the P and Q redundant data calculations associated with the incoming data. When all of the strips have been received, the P+Q checking function will have completed the calculation of P and Q redundant data. In this case, after all the strips and the P or Q data have been received, the P+Q checking function will hold zeroes if all the data and the P and Q data was correct and hold non-zero values if there was an error.
Claims8
A system for checking RAID information, comprising:
- an address compare that determines whether a first address on a system bus corresponds to a predefined data range, a predefined RAID P-data range or a predefined RAID Q-data range, wherein said address compare respectively generates one of a HITD, HITP or HITQ signal in response to the first address being within the predefined data range, the predefined RAID P-data range or the predefined RAID Q-data range;
- a RAID P-data accumulator that stores, in response to the receipt of the HITD or HITP signal, a first result of an exclusive-OR of data stored in said RAID P-data accumulator and data received from said system bus, said data received from said system bus being sent to said first address on said system bus;
- a constant selector that, in response to the receipt of the HITD or HITQ signal and based on said first address on said system bus, selects one of a set of constants that corresponds to said data received from said system bus;
- and,
- a RAID Q-data accumulator that stores, in response to the receipt of the HITD or HITQ signal, a second result of an exclusive-OR of data stored in said RAID Q-data accumulator and a third result of a Galois field multiplication of said one of said set of constants and said data received from said system bus.
2 more elements
A method of checking RAID information, comprising:
- controlling a plurality of storage devices to provide a plurality of RAID strips, said plurality of RAID strips being sent to a plurality of virtual buffers;
- receiving said plurality of RAID strips;
- and,
- a virtual buffer compare that compares an address presented on a system bus with a predefined data range, a predefined RAID P-data range and a predefined RAID Q-data range, wherein said virtual buffer compare respectively generates one of a HITD, HITP or HITQ signal in response to the address being within the predefined data range, the predefined RAID P-data range or the predefined RAID Q-data range;
- accumulating a plurality of P-data values, in response to the receipt of the HITD or HITP signal, corresponding to each of said plurality of virtual buffers and accumulating a plurality of Q-data values in response to the receipt of the HITD or HITQ signal corresponding to each of said plurality of virtual buffers, said plurality of P-data values and said plurality of Q-data values corresponding to said plurality of RAID strips received for each of said plurality of virtual buffers, wherein said plurality of Q-data values are based on a plurality of constants that are selected in response to the receipt of the HITD or HITQ signal and based on a corresponding which one of said plurality of virtual buffers that each of said plurality of RAID strips was sent to, the one of said plurality of virtual buffers that a RAID strip is sent to specified by the address presented on said system bus.
2 more elements
A system for checking RAID information, comprising:
- a virtual buffer compare that compares an address presented on a system bus with a predefined data range, a predefined RAID P-data range and a predefined RAID Q-data range, wherein said virtual buffer compare respectively generates one of a HITD, HITP or HITQ signal in response to the address being within the predefined data range, the predefined RAID P-data range or the predefined RAID Q-data range;
- a selector that, in response to the receipt of the HITD or HITQ signal and based on said address presented on said system bus, selects a Galois Field constant and an accumulator buffer address;
- a Galois Field multiplier that performs a Galois Field multiplication on said Galois Field constant and a block of data that corresponds to said address present on said system bus;
- a P-data exclusive-OR accumulator that stores, in response to the receipt of the HITD or HITP signal, a P-data result of an exclusive-OR operation on said block of data and a stored P-data value corresponding to said accumulator buffer address;
- and,
- a Q-data exclusive-OR accumulator that stores, in response to the receipt of the HITD or HITQ signal, a Q-data result of an exclusive-OR operation on a Galois Field multiplication result and a stored Q-data value corresponding to said accumulator buffer address.
3 more elements
Dependencies are inferred from the claim text.