Reliability, Cost Major Factors in Storage System Selection: Nexsan

The paper cautions businesses not to confuse disk interface type with performance or reliability.

Nexsan, an independent provider of disk-based storage systems, announced a downloadable paper titled, "6 Tips for Selecting HDD and SSD Drives," a free educational resource that provides guidance on selecting the most appropriate hard disk drive or solid state disk drive technology when configuring a storage system for business applications.

There are a number of factors to be considered when selecting drives for a storage environment, the paper explains, including the level of sequential or random access performance needed, storage density, reliability and cost. With today's wide variety of storage devices, many IT professionals are challenged with the multitudes of drive technologies, and this is especially true when selecting the appropriate drives for various data types.

"Hardware matters, and organizations intent on maintaining a robust storage environment should not underestimate the importance of optimizing storage infrastructure with quality hardware components and technology that is aligned with the operating environment," said Arun Taneja, founder and consulting analyst with the Taneja Group. "While technologies have matured to the point where hard drive downtime does not impact business continuity, missteps in drive selection can wreak havoc on operational performance and result in ongoing maintenance issues. We applaud Nexsan's focus on educating the market in this often overlooked area."

The paper warns businesses not to confuse disk interface type with performance or reliability. Historically, Serial Attached SCSI (SAS) and Serial Advanced Technology Attachment (SATA) were used as convenient shorthand for fast or dense disk drives, respectively. Now, however, there are SSD drives with SATA interfaces as well as inexpensive and dense but relatively low-IOPS 7200 RPM drives with SAS or even Fibre Channel interfaces.

Taneja said adding to the confusion is that SATA and SAS refer to disk drive interfaces, whereas SSD refers to a particular kind of internal technology. Selecting a drive technology and interface type can seem complex with considerations of random access performance, sequential performance, cost, density and reliability, but is manageable with the right guidance, the paper explained.

Nexsan research said businesses could achieve the best price per gigabyte (GB) with 3.5" 7200 RPM SATA drives. The paper notes storage vendors have a seemingly endless variety of pricing models, but one constant seems to be that 2.5" systems cost twice as much per gigabyte as 3.5" systems, assuming both are using "enterprise-grade" drives. But as noted previously, a 3.5" drive will be far more reliable.

The company also recommends paying close attention to how much the storage system supplier treats the subject of disk drives. In the spirit of chasing profits, many storage system vendors are moving to a logistics model where drives are not tested in the storage array until it arrives at the customer site. Some no longer perform specific qualification checks between drive hardware and firmware revisions, and the hardware and firmware revisions of all the components of the storage array, which can result in less than stellar outcomes from the start.

"Correct drive choice plays a major role in the overall reliability and performance of a storage system," said Gary Watson, CTO of Nexsan. "At Nexsan, our processes ensure that only drive models performing well in exhaustive engineering trials and testing are delivered to the customer. Equally important, Nexsan's partner ecosystem works with end users to match drives to their intended application, ensuring our systems perform optimally in any business environment."