STA

Author: Jesse Molina, Product Marketing Manager,
PMC-Sierra

The transition from Parallel SCSI to Serial Attached SCSI (SAS) has been taking place for more than three years, since the first SAS hard disk drives (HDDs) were introduced to the market in 2005. Since then, SAS has made its way into a number of applications: from high performance workstations, to Small and Medium Business (SMB), external storage Just a Bunch of Disks (JBODs) and enterprise-class servers. SAS performance, matched with its support for Serial Advanced Technology Attachment (SATA), has made the transition to SAS economical and ideal for addressing many storage applications using a single storage networking infrastructure.

SAS and SATA Compatibility
One of the main reasons that SAS has been able to scale is that it is designed to be compatible with SATA HDDs, which provide the highest capacity at the lowest cost-per-gigabyte of any storage media. In addition, the use of a SATA Active/Active port selector to dual-port a SATA HDD enables fully redundant storage architectures with greater system fault tolerance.

Author: Greg Meythaler, Product Marketing Engineer
Intel

We've all heard the mind-boggling statistics. Data is accumulating at a phenomenal rate, more than doubling every two years. And analysts estimate that even though a whopping 161 exabytes of digital information was created worldwide in 2006, we can expect to generate more than six times that amount - 988 exabytes - in 2010.

Resellers, take note: Digital data growth represents a golden selling opportunity, especially if you can tap into the small-medium business (SMB) segment. Most of these businesses don't have a storage strategy to begin with, let alone a plan for growth. Yet with so much data on the horizon, they will be forced to do something about storage very soon. It's an opportunity you really can't afford to ignore.

But it's a challenging one too. SMBs need storage that can quickly and easily grow with their business and their data. They want the flexibility to go with a DAS strategy one day, and then migrate to NAS or SAN as their needs change. Integration with existing networking equipment is important. Solutions must be powerful and - above all - reliable.

Author; Kent Smith, Product Manager,
LSI Corporation

Exponentially increasing storage requirements in data centers, combined with the implications of regulations such as Sarbanes Oxley and HIPAA, entails large amounts of "business-important" information that must be periodically backed up and accessed while remaining readily available. IT managers are under extreme pressure to find storage solutions that deliver more capacity for less money – without sacrificing reliability or data availability.

In order to address this requirement, nearline enterprise disk array systems are emerging that retain the Fibre Channel (FC) infrastructure on the front-end of the array (in order to fit into existing SANs), while using a mix of Serial Attached SCSI (SAS) and Serial ATA (SATA) drives instead of more expensive FC drives. Such mixed-technology systems reduce costs while retaining the availability, manageability, data integrity and functionality achieved with FC-based storage systems. Though SATA-based storage solutions are ideally suited for the specific workload, capacity, and cost requirements of "secondary storage", SAS-based storage solutions provide performance and reliability comparable to current FC storage solutions.

Author: Suresh Panikar, Director, Branded Products Marketing
Adaptec

One of the most important factors in the growth of Serial Attached SCSI (SAS) is its seamless compatibility with Serial ATA (SATA) storage devices. Until the introduction of SAS, choosing a storage infrastructure meant making a choice to which a business would be committed throughout the long life of the infrastructure. This choice usually reflected a compromise between actual storage needs and budgetary considerations, yet it drove the future of the company's storage infrastructure. Because moving away from the initial decision as needs changed or storage technology evolved always required a tedious and costly upgrade, many companies have clung to an outdated solution that no longer makes sense for their business.

The SAS/SATA compatibility built into SAS components eliminates this long-term commitment to a single storage solution and allows the creation of solutions that can adapt to changing needs with a minimum of cost and complexity. This provides advantages for both end-users and the solutions providers on whom they depend.

Author: Daniel D. Reno, Senior Strategist, Marketing and Strategy, Enterprise HDDs
Hitachi Global Storage Technologies

As noted by Gartner Group in the recent SCSI Trade Association (STA) press release, Serial Attached SCSI (SAS) adoption rates experienced a significant increase in 2006, and SAS is expected to overtake Ultra320 SCSI, or Parallel SCSI, as the interface of choice for a variety of enterprise storage applications this year. Key drivers of SAS adoption have been reduced backplane complexity and improved signal integrity leading to greater reliability. In addition, the interface enables higher data transfer rates and improved scalability over Ultra320 SCSI.

SAS interface compatibility with Serial ATA (SATA) hard drives has been an added benefit, driving overall adoption rates, particularly with the explosion (since 2005) of SATA hard drive use for secondary storage. This ramp is expected to continue given that highest-capacity (one-terabyte) enterprise SATA hard drives recently began shipping in volume.

The combination of high-performance SAS hard drives and ultra high-capacity SATA drives gives builders of these mixed-interface systems and their customers the best of both worlds: tiered storage that is optimized for both performance and reliability, and cost and capacity.

Authors: Chaz Nichols, Global Channel Marketing and Kent Bransford, Sr. Technical Editor
Seagate Technology

"The only constant is change" is surely a familiar (and vexing) maxim to storage managers around the world. Grappling with this ever-present challenge requires a storage interface capable of both meeting today's requirements and seamlessly adapting as priorities inevitably evolve over time. Until recently, addressing an enterprise's broad range of storage needs required a combination of SCSI and Serial ATA (SATA) infrastructures, an inefficient and unwieldy approach.

But now the rules have changed, thanks to Serial Attached SCSI (SAS) and its compatibility with SATA. A key component of the SAS feature suite, this ground-breaking compatibility produces remarkable storage synergies and efficiencies, enabling IT professionals to achieve their performance and capacity objectives with a single SAS infrastructure.

The one-two punch of the SAS/SATA value proposition is simple: SAS hard disk drives (HDDs) deliver the speed, reliability and scalability demanded in high-availability enterprise environments, while high-capacity SATA drives are purpose-built for bulk storage applications, combining low cost per GB and greater reliability and scalability than their parallel ATA ancestors.

Author: Cameron T. Brett, Manager, Product Marketing
PMC-Sierra, Inc.

Serial Attached SCSI (SAS) was designed from the ground up for compatibility with Serial ATA (SATA) disk drives. The benefits of this compatibility include lower total cost of ownership (TCO), increased flexibility and usability, as well as allowing for larger storage capacities in enterprise and small business environments. To understand SAS and SATA compatibility, the enabling components are a good point of departure.

Authors: Franco Castaldini, Sr. Product Marketing Manager
and Kent Bransford, Sr. Technical Editor, Seagate Technology

"If you fear change, leave it here!" may be the lighthearted counsel of cash-strapped baristas, but IT professionals know that proactively adopting change is serious business, a key to maximizing system performance and efficiency. Alas, pioneering storage technologies are often seen as double-edged swords, their gains coming at a stiff price in terms of purchase or deployment and integration.

Fibre Channel (FC) is a prime example of this phenomenon, coupling remarkable throughput and scalability with daunting cost. Beyond the substantial investment required for FC infrastructure itself, Fibre Channel solutions also entail complex deployment and management procedures that require highly specialized (and expensive) expertise not found in many IT departments. Hence FC has typically been limited to enterprises with the needs (and deep pockets) to justify its use.

Serial Attached SCSI (SAS) was specifically architected to avoid such pitfalls. By leveraging the best features of two familiar storage interfaces, SCSI and Serial ATA (SATA), SAS makes it surprisingly easy to upgrade existing SCSI servers and storage arrays. While delivering performance and scalability that rival Fibre Channel, SAS is far simpler (and less costly) to buy, install and maintain.

Author: Tonya Comer, Product Marketing Manager, Industry Standard Servers, HP

Serial Attached SCSI (SAS) holds the promise of the future for SMB users who will eventually need more input/output per second (IOPS) performance, easier connectivity and greater scalability, as storage requirements continue to escalate. As SAS products begin to enter the market in 2005, SMB customers will appreciate the time and effort that has gone into the definition, development, and standardization of this innovative refinement to long-standing SCSI technology.

More affordable for SMB customers than Fibre Channel and more robust and reliable than Serial ATA (SATA), SAS will be able to fulfill the SMB customer requirements and provide the necessary performance and scalability to move data at gigabit speeds—speeds that meet or exceed current storage I/O performance found in Parallel ATA (PATA), SATA, SCSI or Fibre Channel systems.

PMC-Sierra was interviewed by a System Integrator about Serial Attached SCSI's Cable and Connector Features and Uses

Author: Rachelle Trent, Product Marketing Manager
PMC-Sierra
All Figures are courtesy of Molex

The challenges that System Integrators (SIs) encounter when learning how to handle new technologies, new components and especially how to make everything work together, requires research and experience. It helps them acquire the knowledge they need if they have a series of demonstrations of cables and connectors and their uses. The purpose of this article is to provide a mini-demo through the use of illustrations that are clear and easy to understand.

Chaparral Network Storage designs and markets storage appliances that provide simple solutions to common storage networking problems. Chaparral specializes in advanced performance devices that deliver data efficiently within the network, and sells protocol bridges, data routers, RAID controllers and disk array appliances that are network-ready. Maxtor recently had the opportunity to sit down with James Russo, Vice President of Engineering, at Chaparral Network Storage to discuss his views on Serial Attached SCSI (SAS), and how its ability to interoperate with Serial ATA (SATA) disk drives will affect the way storage systems are designed and deployed.

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.

Jim Pascoe
Hitachi Global Storage Technologies

Use of the parallel bus interface, which has long been the industry-standard storage interconnect, is on the verge of decline among the vast majority of system builders. Components that are based on the aging interface are increasingly being replaced by their evolved serial counterparts—Serial Attached SCSI (SAS) and Serial ATA (SATA).

The new serial interfaces are designed to address the bandwidth limitations of their predecessors. They will support faster data transfer rates and more devices per controller, as well as reduce the size and complexity of the cables and connectors (thus enabling smaller, more densely-packed disk arrays). Among the most significant benefits is that incompatibility between SCSI and ATA will finally be addressed.

Authors: Franco Castaldini & Kent Bransford
Seagate Technology

The advent of Serial Attached SCSI coincides with a fundamental change in enterprise data management. Gone are the days when there were only two types of data storage: online and offline. A new concept, near-line or secondary storage, quickly gained acceptance because it recognizes that data has a lifecycle, during which its need for accessibility and security will vary. Rather than a simple online/offline dichotomy, enterprise storage now comprises a continuum along which data can easily migrate as its value and relevance change.