[funsec] Database design.
drsollyp at drsolly.com
Tue Jun 6 18:18:45 CDT 2006
On Tue, 6 Jun 2006, Blue Boar wrote:
> Drsolly wrote:
> >> And you think that's the MTBF you'll get under your use conditions, huh?
> > Yes.
> Really? OK, so here's the possibilities I see. Please pick one or tell
> me what I missed:
> -You know precisely what Maxtor's testing conditions are, and those
> happen to exactly match the conditions under which you use your drive.
> -Maxtor is actually being conservative, and their 1.2M hr claim reflects
> typical field usage. Marketing claims be damned, they're going to tell
> the truth.
> -You've done your own study on the 1.2M hr drives, and came up with the
> same numbers
> >> (Are you're sure that's not the MTBF for drives that aren't powered on?)
> > If you don't power a drive on, it never fails, so the mtbf is infinite.
> Oh, I don't know. I think I could look at a drive that had never been
> powered on, but rusted through after the first 50 years, and declare it
> See, when they publish a MTBF number, I tend to assume that they did
> things like tested with a constant temperature in a vibration-free
> environment, extrapolated beyond what they should have with the sample
> size and length of test, and then failed to publish the margin of error.
> But then, I've been accused of being a pessimist.
Pessimism is good when you're in security.
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