While some other members of the storage industry's chattering class enjoy the process of haranguing array vendors for their seemingly outrageous disk drive markups, I've started recommending that users seeking cost-effective online storage look at BYOD (bring your own drive) storage systems. There are many choices available, from prosumer Data Robotics offerings and SOHO network-attached storage (NAS) boxes from NetGear and QNAP Systems to disk arrays with enterprise aspirations provided by Promise Technology and Infortrend. However, care must be taken when choosing the drives for a BYOD array.
The truth is that the drive vendors haven't really tried to educate anyone but their OEM customers about the subtle differences among the various models of drives they offer at the same capacity point with the same interface. Even friends whom most would consider storage experts haven't spent a lot of time trying to figure out what makes a Western Digital RAID Edition drive different from a Caviar system.
Since most professional storage analysts and advocates are also significant storage consumers--with either a home lab or just every DVD they ever wanted available through Apple TV or Boxee around the house--many have ended up with a Data Robotics Drobos system of one kind or another. Data Robotics has even seeded units to a few of us, so I have a Drobo Elite in the lab courtesy of those nice folks.
So we see tweets and blog posts like "Which Hard Disk Drives Should You Use in a Drobo?" from fellow Network Computing blogger Stephen Foskett. The responses to the blog describe users' vendor and model experiences, which are, of course, based on sample sizes too small to be really meaningful, but not the technology.
So what makes a "nearline" drive different than a desktop drive with the same capacity? I set out to answer that question a few months ago and sent e-mails to my contacts at the usual drive vendors. None had any real answers. The best response was, "No one that knows the answer to that question is press-trained."
