Author: Tonya Comer, Product Marketing Manager, Industry Standard Servers
HP
Just in time for today’s storage explosion, Serial Attached SCSI (SAS) hard drive options provide a scalable, flexible, better performing and efficient solution for servers and for storage enclosures that go beyond the inherent limits of parallel technology. A recent study at the University of California at Berkeley found that the rate of storage performance is growing 30 percent year over year. According to the report, physical media is defined as “print, film, magnetic and optical – and seen or heard in four information flows through electronic channels – telephone, radio and TV and the Internet,” that will at some point be stored for retrieval. This holds true at the enterprise data center level with data collection spanning email, security, and online and financial transactions.
SAS Leverages Other Storage Technologies
In looking at the available storage technologies, including the strengths of parallel SCSI, SAS creatively melds the best of each. SAS leverages some high-end features from Fiber Channel such as native dual-port hard drives, multi-initiator support and full-duplex communication, plus the physical interface leveraged from SATA for compatibility and investment protection. SAS combines them with the reliability and ease of use of traditional SCSI technology.
SAS is much more scalable and flexible than the parallel technology it is replacing. In the past, with parallel technology, users had to make a decision on a single storage interface when buying a server or storage enclosure. Today’s SAS technology offers SATA compatibility, enabling data center managers to implement both within the same server or storage enclosure, minimizing technology investments while maximizing IT user choice and ease of deployment.
Smaller, Cooler Drives
Data centers are constantly moving to denser and smaller servers and storage enclosures. Data center managers are trying to consolidate more into less space, or more into the same amount of space. One benefit of SAS technology is that the physical connector on the hard drive is about one quarter the size of what it was for parallel technologies. The connector on the hard drive no longer dictates the size of the drive, allowing SAS drives to be designed into a much smaller form factor. Small form factor SAS drives require about half the power of 15K 3.5″ SCSI drives and therefore generate less heat. Small form factor drives allow for additional space at the front of the server which allows more air to be drawn through the equipment for improved cooling. A full rack of servers and storage enclosures with small form factor hard drives, typically reduces power consumption by 500 to 1000 watts.
The key to increased hard drive performance is to boost the number of I/Os. The simplest way to increase storage performance is to add more hard drives into a server or storage enclosure and spread the data across multiple disks, distributing the workload among all of the hard drives. With smaller form factor drives, more drives can physically fit into a server or storage enclosure. More drives translate into increased I/O performance. With Ultra320 SCSI hard drives today, a typical server might contain six hard drives. SAS small form factor drives allow room for additional hard drives, which in return increases performance, while still reducing power consumption and improving airflow.
Summary
The future of storage is SAS because it gives customers ultimate configuration options, flexibility, and simplicity in their storage environments. SAS was brought to market to meet the changing demands of mainstream enterprise class storage system customers. SAS holds the promise of the future for enterprise users demanding superior choice, easier connectivity, and greater scalability as server and storage requirements continue to escalate.
