Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261585AbVETUxu (ORCPT ); Fri, 20 May 2005 16:53:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261582AbVETUxu (ORCPT ); Fri, 20 May 2005 16:53:50 -0400 Received: from gannon.phys.uwm.edu ([129.89.61.108]:57031 "EHLO gannon.phys.uwm.edu") by vger.kernel.org with ESMTP id S261585AbVETUxr (ORCPT ); Fri, 20 May 2005 16:53:47 -0400 Date: Fri, 20 May 2005 15:53:36 -0500 (CDT) From: Adam Miller X-X-Sender: amiller@gannon.phys.uwm.edu To: Grzegorz Kulewski cc: Lennart Sorensen , linux-kernel@vger.kernel.org Subject: Re: software RAID In-Reply-To: Message-ID: References: <20050520200334.GF23621@csclub.uwaterloo.ca> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1866 Lines: 43 Hi, Yes, I want to know if the bad sector on disk A will be reallocated when disk B tries to write to disk A. Adam On Fri, 20 May 2005, Grzegorz Kulewski wrote: > On Fri, 20 May 2005, Lennart Sorensen wrote: > >> On Fri, May 20, 2005 at 12:56:13PM -0500, Adam Miller wrote: >>> We're looking to set up either software RAID 1 or RAID 10 using 2 SATA >>> disks. If a disk in drive A has a bad sector, can it be setup so that the >>> array will read the sector from drive B and then have it rewrite the >>> bad sector on drive A? Please CC me in the response. >> >> If a harddisk has a bad sector that is visible to the user (and hence >> not remapped by the drive) then it is time to retire the drive since it >> is out of spares and very damaged by that point. >> >> If you have a bad sector, it doesn't go away by writing to it again. On >> modern drives, if you see bad sectors the disk is just about dead, and >> will probably be seen as such by the raid system which will then stop >> using the disk entirely and expect you to replace it ASAP. > > What do you mean "see bad sectors"? > > Modern drives are trying to relocate sectors that can become bad in short > time. But this does not work 100% reliably. And sometimes disk wants to > relocate sector but the sector can not be read anymore. If this happens disk > will return read error when reading the sector _but_ when you will write it > again it will relocate it (with new data). And I think this was the idea > behind first post... To allow disk A to relocate not readable sectors with > correct data from disk B. > > > Grzegorz Kulewski > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/