STA

Author: Mike Micheletti, Product Manager
LeCroy Corporation

With Serial Attached SCSI (SAS) products now entering the market, system integrators and storage vendors are accelerating their transition to serial-based storage infrastructure. By taking the lead on delivering SAS-based solutions, these vendors can build high performance sub-systems while developing valuable expertise in this next generation direct-attach storage technology.

As storage integrators ramp their SAS design and validation efforts, they may benefit from using specialized test equipment to accelerate product qualification. Below are three protocol-level test tools that are playing a key role in validating SAS components as ready for enterprise-worthy applications.

Author: Franco Castaldini and Kent Bransford
Seagate Technology

Serial Attached SCSI (SAS)/Serial ATA (SATA) compatibility produces unprecedented storage synergies and efficiencies, enabling enterprises to meet both performance and capacity requirements with a single SAS infrastructure. SAS drives deliver the speed, reliability and scalability demanded in high-availability enterprise environments, while high-capacity SATA nearline drives are purpose-built for bulk storage applications, combining low cost per GB and enhanced reliability.

And now the SAS value proposition grows even stronger with the arrival of small form factor (SFF) 2.5-inch enterprise drives. These drives are spearheading a new class of high-I/O-density storage solutions that facilitate rapid and cost-effective storage consolidation. SFF 2.5-inch drives are 70 percent smaller than conventional 3.5-inch 10K drives, enabling them to deliver 130-150 percent greater system performance in the same footprint. They also use 40 percent less power and run cooler, reducing airflow requirements and enabling greater storage density.

Author: Tonya Comer, HP

Three years ago the Serial Attached SCSI (SAS) and Serial ATA (SATA) industry working groups developed specifications for serial I/O technologies that will provide the flexibility and performance that IT managers need for storage products and solutions in the future. SCSI Trade Association (STA) member companies have worked together in the interim developing SAS technology to ensure quality products for reliable, quick-time-to-market SAS solutions. SAS solutions will be implemented in enterprise-class data centers, delivering the full functionality of enterprise-class systems and subsystems such as hard disk drives (HDDs). SATA solutions will be implemented in desktop PCs and low-cost, non-mission-critical server storage solutions.

Author: David Allen
Vitesse Semiconductor

With the advent of new technology often comes new terminology and updated definitions for familiar concepts. Engineering and standards communities strive to precisely define concepts and functions using terminology applicable to the technology. The Serial Attached SCSI (SAS) standards community is no different, and has defined specific terminology for the physical and link layer functions surrounding SAS links. Addressed in this article is a clarification of the definitions and terminology surrounding SAS connections.

Author: David Woolf, Senior Storage Research Engineer and Principle SAS Consortium Engineer,
University of New Hampshire-InterOperability Laboratory (UNH-IOL)

This is an exciting time for Serial Attached SCSI (SAS). Its development curve has been extraordinarily smooth and swift, products are now launching and market entry will accelerate as 2005 goes forward. The last of the dust clouds are dissipating, and it's becoming clearer what role SAS will play in the near- and not-so-near-term data center market.

Greasing the Skids
The rapid SAS market ramp-up owes much to the forethought and careful planning of key engineering players and organizations like the SCSI Trade Association (STA). In fact, SAS' smooth transition from the engineering white board to the marketplace should be taken as a model for successful technology development. This process succeeded for two key reasons: First, SAS didn't reinvent the wheel. Its development incorporated and built upon older, well-established technologies such as SCSI and the trusted XAUI (see definition two paragraphs below) physical layer. Second, interoperability tests were built into the development process from the start. Amazingly, this is not necessarily the rule with new technologies.