Disk Array Architectures

Walt Burkhard, UC San Diego


A variety of applications, such as on-line transaction processing and scientific computing, require high throughput from cost-effective storage subsystems. Disk arrays offer significant advantages over individual disks. By aggregating multiple disk drives, arrays achieve better transfer bandwidths and potential reductions on seek and rotational latencies due to smaller-sized form factors. Reliability is obtained by storing redundant data. Data is grouped into stripes that contains redundant data as well. If a disk is unavailable, all the stripe units mapped to the disk can be recovered by virtue of the redundant data.

In declustered data organizations, each stripe is mapped to k of the n disks thereby achieving significant performance improvements during degraded operation. These layouts are based upon balanced incomplete block designs and parity declustering is an example. We will present several alternative approaches that provide very attractive implementations as well as excellent run-time performance.


	Department of Computer Science and Engineering  
	UC San Diego
	Department of Electrical Engineering 
	Princeton University

	Ph.D. UC Berkeley	1969