From mboxrd@z Thu Jan 1 00:00:00 1970 From: Piergiorgio Sartor Subject: Re: mismatch_cnt again Date: Sat, 07 Nov 2009 17:23:53 +0100 Message-ID: <4AF59F19.1080409@lazy.lzy> References: <4AF4C247.6050303@eyal.emu.id.au> <4AF4D323.6020108@panix.com> <4AF5268D.60900@eyal.emu.id.au> <4877c76c0911070008m789507f8h799d419287740ca5@mail.gmail.com> <87tyx6tpcb.fsf@frosties.localdomain> <4AF58B20.3000409@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4AF58B20.3000409@redhat.com> Sender: linux-raid-owner@vger.kernel.org To: Doug Ledford Cc: Goswin von Brederlow , Michael Evans , Eyal Lebedinsky , linux-raid list List-Id: linux-raid.ids On 11/07/2009 03:58 PM, Doug Ledford wrote: [...] > I'm very quickly starting to become dubious of the current mismatch_cnt > implementation. I think a kernel patch is in order and I may just work > on that today. Here's the deal: a non-0 mismatch count is worthless if > you don't also tell people *where* the mismatch is so they can > investigate it and correct it. You're perfectly right. And this, again, fits in the discussion of RAID-6 error check and, potentially, repair. Ideally the log should tell which (RAID) address has a mismatch and, in case of RAID-6, if a specific device could be faulty at that position. This would be already quite a huge step forward in improving the overall reliability of the RAID sub-system. Side note: in F11 there is this cron.weekly raid-check, but nothing is reported (per email to root) in case of mismatch. Is there any plan to add a such a facility? Thanks. bye, -- piergiorgio