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2a= Drive manufacturers _do_ design server drives to be more reliable than consumer drives This is easily provable by opening the clam shells of a Seagate consumer HD and a Seagate enterprise HD of the same generation and comparing them. In addition to non-visible quality differences in the actual media (which result in warranty differences), there are notable differences in the design and materials of the clam shells. HOWEVER, there are at least 2 complicating factors in actually being able to obtain the increased benefits from the better design:
*HDs are often used in environments and use cases so far outside their manufacturer's suggested norms that the beating they take overwhelms the initial quality difference. For instance, dirty power events or 100+F room temperatures will age HDs so fast that even if the enterprise HDs survive better, it's only going to be a bit better in the worst cases.
*The pace of innovation in this business is so brisk that HDs from 4 years ago, of all types, are of considerably less quality than those made now. Someone mentioned FDB and the difference they made. Very much so. If you compare HDs from 4 years ago to ones made 8 years ago you get a similar quality difference. Ditto 8 vs 12 years ago. Etc.
The reality is that all modern HDs are so good that it's actually quite rare for someone to suffer a data loss event. The consequences of such are so severe that the event stands out more than just the statistics would imply. For those using small numbers of HDs, HDs just work.
OTOH, for those of us doing work that involves DBMSs and relatively large numbers of HDs per system, both the math and the RW conditions of service require us to pay more attention to quality details.
Like many things, one can decide on one of multiple ways to "pay the piper".a= The choice made by many, for instance in the studies mentioned, is to minimize initial acquisition cost and operating overhead and simply accept having to replace HDs more often.
b= For those in fields were this is not a reasonable option (financial services, health care, etc), or for those literally using 100's of HD per system (where statistical failure rates are so likely that TLC is required), policies and procedures like those mentioned in this thread (paying close attention to environment and use factors, sector remap detecting, rotating HDs into and out of roles based on age, etc) are necessary.
Anyone who does some close variation of "b" directly above =will= see the benefits of using better HDs.
At least in my supposedly unqualified anecdotal 25 years of professional experience.
Ron Peacetree At 10:35 PM 4/6/2007, Bruce Momjian wrote:
In summary, it seems one of these is true: 1. Drive manufacturers don't design server drives to be more reliable than consumer drive 2. Drive manufacturers _do_ design server drives to be more reliable than consumer drive, but the design doesn't yield significantly better reliability. 3. Server drives are significantly more reliable than consumer drives.
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