Author: Michael Micheletti, Product Manager, LeCroy Corp.
Serial Attached SCSI (SAS) is a storage interface developed to meet the needs of enterprise-class storage applications. Leading solution vendors are rapidly adopting this new standard because it offers superior performance while preserving compatibility with legacy SCSI applications. Central to the SAS value proposition is its ability to scale storage systems beyond the limits of today’s parallel SCSI by using a switching technology called expanders. Designed to provide a fan-out architecture for SAS, expanders allow SAS initiators to connect up to 16,000 physical links per domain. Yet this is only one aspect of SAS' scalability as an enterprise-class storage interface.
Another important advantage of SAS is interoperability with Serial ATA (SATA) disk drives. The SAS specification defines an electrical and physical connection interface within the backplane that is form-factor compatible with SATA. This feature is ushering in a new approach to storage system design, enabling manufacturers, integrators and users to populate a single storage enclosure with either SAS or SATA disks. Enterprise-class storage systems can be equipped with high performance SAS drives for mission-critical applications. The same storage enclosure can also be introduced with lower cost SATA drives to address segments of the market that value capacity over performance.
