Lsi Logic Corporation

Lsi Corporation

Ragendra Mishra

Paresh Chatterjee

Chayan Biswas

Basavaraj Gurupadappa Hallyal

Senthil Thangaraj

Narasimhulu Dharani Kotte

The present invention provides a method for transmitting a non-SCSI command via a SCSI command. A CDB for the SCSI command is provided. The CDB includes bytes byte, byte, byte, . . . , byte_n, in which byteincludes an opcode for the SCSI command. An opcode for the non-SCSI command is loaded into byte. When the non-SCSI command is not greater than a fixed number of bytes, the non-SCSI command is loaded into at least one byte of the CDB, which includes byte. Data associated with the non-SCSI command is transmitted via a data phase associated with the SCSI command.

Methods of transmitting non-SCSI commands involving loading opcode in command descriptor block (CDB) bytes and non-SCSI commands into remaining CDB bytes

Systems and methods for maintaining cache coherency between a first controller and a redundant peer controller while reducing communication overhead processing involved in the coherency message exchange. Header or meta-data information is accumulated in a buffer in a first controller along with updated cache data (if any) and forwarded to the peer controller. The accumulating information may be double buffered so that a buffer is filling as a previously filled buffer is transmitting to the peer controller. The peer controller processes the received information to update its mirror cache to maintain coherency with the first controller's cache memory with respect to dirty data. The method and systems avoid the need to update cache coherency in response to every flush operation performed within the first controller to thereby improve overall system performance.

Systems and methods for cache synchronization between redundant storage controllers

Methods and structure for initializing a RAID storage volume substantially in parallel with processing of host generated I/O requests. Initialization of a RAID volume may be performed as a background task in one aspect of the invention while host generated I/O requests proceed in parallel with the initialization. The initialization may preferably the performed by zeroing all data including parity for each stripe to thereby make each stripe XOR consistent. Host generated I/O requests to write information on the volume may utilize standard read-modify-write requests where the entire I/O request affects information in a portion of the volume already initialized by background processing. Other host I/O requests use standard techniques for generating parity for all stripes affected by the write requests. These and other features and aspects of the present invention make a newly defined RAID volume available for host processing is quickly as possible.

Methods and structure for rapid background initialization of a RAID logical unit

The present invention is directed to a system and method for increased data availability. In an aspect of the present invention, a method includes receiving a SMART indication from a data storage device included in a plurality of data storage devices configured as a RAID array. Data from the data storage device which originated the SMART indication is replicated to a second data storage device. The second data storage device was not originally configured in the RAID array with the plurality of data storage devices for data storage. The data storage device which originated the SMART indication from the RAID array is removed, thereby resulting the second data storage device and the plurality of data storage devices configured as a RAID array.

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Fremont, CA, United States of America

Ragendra Mishra