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|ATA vs. SCSI disk performance|
In a converged environment, NAS gateways sit alongside block-savvy application servers to enable access to back-end SAN storage. But companies that opt for a multivendor solution often struggle to find a mix of products that will work well together.
Another way to view reliability
There's a certain healthy paranoia existing regarding disk drive reliability. After all, most IT professionals have had serious problems at some time in their past with the loss of a disk drive. But the real requirement is for data availability--not necessarily drive reliability. If other technologies and techniques can be used to achieve data availability, then the reliability of disk drives isn't quite as critical.
One of the fundamental technologies increasing data availability is RAID. Since most businesses can't afford interruptions because of an individual disk drive failure, IT professionals have widely adopted RAID with disk subsystems that support hot-swappable disk drives and hot sparing. The important point is that data availability is provided at a higher level than the disk drive by products such as volume management software and RAID controllers. Just as space allocation is provided as a high-level function by file systems, access to data is provided at a greater level by software and/or controller technology.
Even so, reliability is a primary requirement for disk drives and disk drive vendors are accustomed to competing on reliability metrics. The market punishes vendors who sell drives of substandard quality by avoiding their products. While it's true that server drives are designed for more demanding usage than desktop and laptop drives, it's wrong to say that desktop drives are manufactured to poor quality standards. Most of the components inside disk drives are identical across server and desktop product families today. There's no reason to believe that desktop drives can't be used in enterprise-quality disk subsystems with higher-level data availability features.
The interfaces used for server and desktop drives have been one of the ways disk drive manufacturers have distinguished the two classes of drives. Server drives are made with SCSI or Fibre Channel (FC) interfaces, whereas desktop drives today use the ATA interface. While there are some real cost differences between the interfaces, they are relatively small, and not nearly as great as the cost difference between two similar disk drives would indicate.
This was first published in October 2003