Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751425AbWHIXSg (ORCPT ); Wed, 9 Aug 2006 19:18:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751435AbWHIXSf (ORCPT ); Wed, 9 Aug 2006 19:18:35 -0400 Received: from mail.suse.de ([195.135.220.2]:39841 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1751425AbWHIXSe (ORCPT ); Wed, 9 Aug 2006 19:18:34 -0400 From: Neil Brown To: Jan Engelhardt Date: Thu, 10 Aug 2006 09:18:24 +1000 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17626.27968.132243.825703@cse.unsw.edu.au> Cc: Michael Tokarev , Alexandre Oliva , linux-raid , linux-kernel Subject: Re: modifying degraded raid 1 then re-adding other members is bad In-Reply-To: message from Jan Engelhardt on Wednesday August 9 References: <17624.29070.246605.213021@cse.unsw.edu.au> <44D8732C.2060207@tls.msk.ru> <17625.4242.910985.97868@cse.unsw.edu.au> X-Mailer: VM 7.19 under Emacs 21.4.1 X-face: [Gw_3E*Gng}4rRrKRYotwlE?.2|**#s9D >> Why we're updating it BACKWARD in the first place? > > > >To avoid writing to spares when it isn't needed - some people want > >their spare drives to go to sleep. > > That sounds a little dangerous. What if it decrements below 0? It cannot. md decrements the event count only on a dirty->clean transition, and only if it had previously incremented the count on a clean->dirty transition. So it can never go below what it was when the array was assembled. NeilBrown - 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/