From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luca Berra Subject: Re: Read errors on raid5 ignored, array still clean .. then disaster !! Date: Mon, 1 Feb 2010 14:27:03 +0100 Message-ID: <20100201132703.GA29849@maude.comedia.it> References: <4B5F6C73.30707@texsoft.it> <20100127074138.GA9607@maude.comedia.it> <20100129214852.00e565c4@notabene> <4B647E0E.6050609@texsoft.it> <4B64A779.6070809@shiftmail.org> <4B65943A.4040800@shiftmail.org> <4B66B367.6030803@texsoft.it> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Return-path: Content-Disposition: inline In-Reply-To: <4B66B367.6030803@texsoft.it> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Mon, Feb 01, 2010 at 11:56:39AM +0100, Giovanni Tessore wrote: > Yes, the new behaviour is good for raid-6. > But unsafe for raid 1, 4, 5, 10. > The old behaviour saved me in the past, and would have saved also this > time, allowing me to replace the disk as soon as possible.. the new one > didn't at all... The 'new' behaviour was implemented because kicking drives out of an array on a read error may prevent the array to be repaired at all. modern drives _have_ correctable read errors, it is a fact. So if md kicked drives on read error it is also possible to lose all data on multiple failures (read errors on more than one drives, or read-errors when sparing), that could have been recovered. > The new one must at least clearly alert the user that a drive is getting > read errors on raid 1,4,5,10. Agreed, now let's define 'clearly alert', besides syslog. L. -- Luca Berra -- bluca@comedia.it Communication Media & Services S.r.l. /"\ \ / ASCII RIBBON CAMPAIGN X AGAINST HTML MAIL / \