From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roy Sigurd Karlsbakk Subject: Re: Chances of silent errors? Date: Tue, 22 Jan 2013 11:55:38 +0100 (CET) Message-ID: <24463267.2.1358852138003.JavaMail.root@zimbra> References: <28222077.12.1358798287217.JavaMail.root@zimbra> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <28222077.12.1358798287217.JavaMail.root@zimbra> Sender: linux-raid-owner@vger.kernel.org To: linux-raid Raid List-Id: linux-raid.ids > 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 driv= e > 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 an= d 1:10^16 for 10k and 15k enterprise drives (or most do). I was under t= he impression that "nearline" / 7k2 enterprise drives were the same th= ing as desktop drives, only with a slightly different firmware (TLER an= d friends =3D> 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 enterpris= e and desktop 7k2 drives? Is this 10-fold difference between error rate= s real, or is it just marketing? Vennlige hilsener / Best regards roy -- Roy Sigurd Karlsbakk (+47) 98013356 roy@karlsbakk.net http://blogg.karlsbakk.net/ GPG Public key: http://karlsbakk.net/roysigurdkarlsbakk.pubkey.txt -- I all pedagogikk er det essensielt at pensum presenteres intelligibelt.= Det er et element=C3=A6rt imperativ for alle pedagoger =C3=A5 unng=C3=A5= eksessiv anvendelse av idiomer med xenotyp etymologi. I de fleste tilf= eller eksisterer adekvate og relevante synonymer p=C3=A5 norsk. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html