Author: Levi Norman, ISS Storage Strategist, Industry Standard Servers
From the time SAS was envisioned to this point, we have heard time and again it is to be much more than parallel SCSI ever hoped to be. It should deliver unsurpassed ROI, new and unique configurations and unparalleled performance gains, etc. It actually began as an engineering dilemma of how to overcome the issue of speeding up the bus and keeping all the data synchronized, on path, and ready to arrive at its destination in a timely and safe manner. pSCSI could no longer guarantee the safety or even the timely arrival of the 'payload,' thus the look elsewhere for a competent answer.
The idea of serial technology has been around for quite some time in varying forms and formats, alongside varying speeds and levels of security and connectivity. But the idea of using it cost-effectively outside of the Fibre Channel world with a cost-effective connection, (although smaller, stronger connectors, thanks to IB and ATA), had only recently been thought of. Long story short, SAS was born. It was born with 3Gb speeds, it was born with great expandability above and beyond pSCSI, and it is born with better inherent management than pSCSI.
ROI on a data center is easily calculated, right? Yes, if you are starting from the ground up. What about those folks that have a datacenter today? What do they do? How do they realize an immediate benefit? How do they calculate it? First, SAS is inherently SCSI and inherently connects into the architecture, yet immediately has architectural and performance benefits. The drives became more robust as they became smaller, point-to-point architectures sped up the transactions, and scalability went up nearly tenfold. Results get better immediately for even the existing datacenter. And secondly, HP as a company, offers a host of methods to measure performance and transactions with a variety of tools and industry monitored tests.