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From: Roy Sigurd Karlsbakk <roy@karlsbakk.net>
To: linux-raid Raid <linux-raid@vger.kernel.org>
Subject: Re: Chances of silent errors?
Date: Tue, 22 Jan 2013 11:55:38 +0100 (CET)	[thread overview]
Message-ID: <24463267.2.1358852138003.JavaMail.root@zimbra> (raw)
In-Reply-To: <28222077.12.1358798287217.JavaMail.root@zimbra>

> Coming from the zfs world, I've heard a few talk about the chances of
> "silent errors", meaning the checksum on the drives match, but the
> data being bad because of matching checksum (aka collisions). Does
> anyone in here know the relative chance of something like that
> happening with the checksums of current harddisks? Is the 1:10^14 or
> 1:10^15 chances for a URE in regard to this, or is that when the drive
> reports an error, or those two combined?

A follow-up here. I see drive manufacturers report the chance of an URE is 1:10^14 for desktop drives, 1:10^15 for 7k2RPM enterprise drives and 1:10^16 for 10k and 15k enterprise drives (or most do). I was under the impression that "nearline"  / 7k2 enterprise drives were the same thing as desktop drives, only with a slightly different firmware (TLER and friends => don't do anything as stupid as going into "deep recovery mode" like some desktop drives do).

Any idea if there's a real difference between the hardware on enterprise and desktop 7k2 drives? Is this 10-fold difference between error rates real, or is it just marketing?

Vennlige hilsener / Best regards

roy
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Roy Sigurd Karlsbakk
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  parent reply	other threads:[~2013-01-22 10:55 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-21 19:58 Chances of silent errors? Roy Sigurd Karlsbakk
2013-01-21 22:16 ` Roger Heflin
2013-01-21 22:39 ` Peter Grandi
2013-01-21 23:00 ` Chris Murphy
2013-01-22 10:55 ` Roy Sigurd Karlsbakk [this message]
2013-01-22 16:28   ` Chris Murphy
2013-01-22 18:33     ` Roy Sigurd Karlsbakk

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