From mboxrd@z Thu Jan 1 00:00:00 1970 From: Justin Piszcz Subject: Re: detection/correction of corruption with raid6 Date: Fri, 5 Dec 2008 16:09:00 -0500 (EST) Message-ID: References: <1228510833.16555.76.camel@localhost> <1228511195.16555.78.camel@localhost> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Return-path: In-Reply-To: <1228511195.16555.78.camel@localhost> Sender: linux-raid-owner@vger.kernel.org To: Redeeman Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Fri, 5 Dec 2008, Redeeman wrote: > On Fri, 2008-12-05 at 16:02 -0500, Justin Piszcz wrote: >> >> On Fri, 5 Dec 2008, Redeeman wrote: >> >>> Hello. >>> >>> I was looking at the PDFs linked to from the wiki, and found this: >>> http://kernel.org/pub/linux/kernel/people/hpa/raid6.pdf >>> >>> More specifically, section 4, starting on page 8. >>> >>> Am I understanding this correctly, in that with raid6, linux is capable >>> of detecting if the content on 1 disk is corrupted, and reconstruct it >>> from the remaining disks? >> >> I ran md/raid6 for awhile, do you mean remap the bad sector on the fly? >> Linux/md raid does not do this afaik. > > No, i mean, if one disk does silent corruption What would the error look like? Both md/Linux & in the 3ware manual recommend you run a 'check' across the raid at least once a week (3ware/raid-verify) and md/Linux in Debian runs a check once a month I believe to eliminate these issues. If you are asking whether a read error of a latent sector from the one disk will result it reading the data from the second disk that is a good question. Justin.