From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roy Sigurd Karlsbakk Subject: Re: Checksumming RAID? Date: Tue, 27 Nov 2012 14:09:30 +0100 (CET) Message-ID: <2920513.16.1354021770710.JavaMail.root@zimbra> References: <50B4B40B.3000807@hesbynett.no> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <50B4B40B.3000807@hesbynett.no> Sender: linux-raid-owner@vger.kernel.org To: David Brown Cc: Linux Raid , Bernd Schubert List-Id: linux-raid.ids > One way to handle this at md block level would be to have an option > for > raid arrays to always do a full stripe read and consistency check > whenever a block is read. If the consistency check fails (without any > errors being indicated from the drives), the array should simply > return > a read error - it should /not/ attempt to recover the data (since it > can't tell which parts are the real problem). If arrays with this > option are used as first-level arrays, with a "normal" md raid array > (raid1, raid5, etc.) on top, then the normal raid recovery process > will > replace the bad data and initiate a new write to correct the > undetected > read error. I think this would perhaps give you the level of > reliability you are looking for, and be suitable for big arrays > (indeed, > it would be unsuitable for small arrays as you need at least two > levels). If this system is running RAID-6, recovery should be possible to check = both parity chunks, right? 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