Have you heard that high capacity, storage-intensive disk drives including ATA (also known as parallel ATA and PATA) and SATA (Serial ATA) are not reliable, have poor performance and should not be used in enterprise environments? A closer look reveals that this is not entirely true. When used properly, SATA is reliable technology. The issue is not the technology itself, but rather the way it is used -- or more accurately, misused.
Trends regarding capacity-intensive storage include higher capacity disk drives (moving from 400 gigabytes (GB) to 500 GB and larger capacity), reduced footprint (physically smaller) and faster support (shifting from 5,400 rpm to 7,200 rpm and even 10,000 rpm) for native command queue, which is similar to the SCSI command tag queue for better performance.
Storage array vendors are adding more intelligence into their controllers and firmware to leverage high-capacity disk drives in order to prolong their life and improve service delivery. Some storage controller and storage system vendors have introduced new data protection techniques to support high-capacity disk drives. These data protection techniques include multi-disk parity schemes using RAID-6 (dual parity). Other examples include predicative copy and data migration schemes to proactively move data from a disk that is likely to fail (avoids or mitigates the overhead of a drive rebuild).
Some vendors like Copan Systems refer to this as disk aerobics where they power down disk drives that are not being used to prolong the drive life and stay within disk drive duty cycle parameters. Vendors including EMC Corp., Engenio Information Technologies, Hitachi Data Systems, HP, IBM, Network Appliance Inc., Sun Microsystems Inc., StorageTek, Xiotech Corp. and Xyratex leverage good packaging including power, cooling, noise and vibration dampening to help improve the performance and reliability of high capacity disk drives. One of the key things you can do to maximize the performance and availability of a high-capacity disk drive is to use it for what it was designed to do. Most challenges and issues that I hear about -- with regard to capacity-intensive disk drives, at least form the major vendors -- are tied to product configuration and use. In other words, the technology is being made to perform tasks it was not intended to be used for.
Some additional tips and recommendations include:
There are many myths and a lot of fear, uncertainty and doubt about SATA and high-capacity disk drives in the industry today. The key is not to be afraid of this technology and instead become more aware and respectful of strengths, weakness and how to use it as part of a tiered storage environment. You can learn more about what type of disk drive to use for different applications in the free white paper "What Type of Disk Drive to Use", which is available on the Evaluator Group Web site.
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About the Author: Greg Schulz is a senior analyst with the Evaluator Group responsible for distributed storage, networking, and associated platform management software. Greg is also author of the book "Resilient Storage Networks" (Elsevier). Greg can be reached at firstname.lastname@example.org