System and Method for Efficient Redundancy on a Single DASD
Original Publication Date: 2000-Nov-01
Included in the Prior Art Database: 2003-Jun-18
Disclosed is a system and method for efficient redundancy on a single direct access storage device (DASD). The invention uses multiple copies of data to: reduce access time reduce error recovery time reduce the number of required error correcting code (ECC) bytes increase reliability increase sustained data rate Throughout the mid-80s and 90s, data capacity on DASDs has grown at a much faster rate than the rate at which data can be retrieved. To combat this, many system designers implemented redundant array of independent disks (RAID) solutions to stripe data across multiple drives, thereby speeding the access to the data by allowing multiple drives to retrieve a portion of the information. The use of RAID solutions has worked well in the high-end server market but is not a reasonable approach on lower cost workstation and desktop systems. In fact, it appears that hard drives will soon outstrip the ability of RAID systems to deal with the drive's dramatically increased storage capacities. The next logical step seems to be in the direction of placing RAID-type functionality in the drives themselves. This invention is a step in that direction.