From mboxrd@z Thu Jan 1 00:00:00 1970 From: Giovanni Tessore Subject: Re: md road-map: 2011 Date: Wed, 16 Feb 2011 12:28:42 +0100 Message-ID: <4D5BB4EA.8030907@texsoft.it> References: <20110216212751.51a294aa@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110216212751.51a294aa@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi Neil, I apreciate very much the Bad Block Log feature, as I had big troubles with read errors during recovery of a degraded RAID-5 array. It seems to me a very good idea to just fail a stripe or even a single block (the smallest possible unit of information possibly) if the read error is unrecoverable, letting the remainig 99.99..% of the device still online and available (that is, return the unrecoverable read error to the 'caller' as would do a single disk). Also having the list of bad block availabe into sysfs is a very useful feature. Still regarding to correctable read errors, how are they currently managed with RAID-1? If a read error occurs on sector XZY of disk A, the same sector XYZ is get from another disk (ramdomly) in the same array and rewritten to disk A? (for RAID456 it's reconstructed from parity, and it's clearly much safer). Regards. On 02/16/2011 11:27 AM, NeilBrown wrote: > I all, > I wrote this today and posted it at > http://neil.brown.name/blog/20110216044002 > > I thought it might be worth posting it here too... > > NeilBrown -- Cordiali saluti. Yours faithfully. Giovanni Tessore