From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753533AbZKUU6k (ORCPT ); Sat, 21 Nov 2009 15:58:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752719AbZKUU6j (ORCPT ); Sat, 21 Nov 2009 15:58:39 -0500 Received: from mail-vw0-f192.google.com ([209.85.212.192]:55078 "EHLO mail-vw0-f192.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752508AbZKUU6i (ORCPT ); Sat, 21 Nov 2009 15:58:38 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; b=MH6oC5xdw783qM7hXCz2E2Ukv/ADXZ20wuht76vslbASYE8fjmHclStY3ovk0Kj7WC BQMz6/rGOGcrWwGyZz+WPsjyvpazc/8vij8yEFlyJf2NCUUHKPdbmYSW67PJezRXm3ww kuYtZcTxAXCppHSX7uDBcHZTSM+p8J+Ez+qMA= MIME-Version: 1.0 In-Reply-To: <20091121203645.60d68d11@mjolnir.ossman.eu> References: <20091008163952.679572b5@mjolnir.ossman.eu> <20091121170355.7540d169@mjolnir.ossman.eu> <20091121203645.60d68d11@mjolnir.ossman.eu> Date: Sat, 21 Nov 2009 13:58:41 -0700 X-Google-Sender-Auth: b68f9143b9009f36 Message-ID: Subject: Re: Raid not shutting down when disks are lost? From: Dan Williams To: Pierre Ossman Cc: neilb@suse.de, LKML Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Nov 21, 2009 at 12:36 PM, Pierre Ossman wrote: > Or is there perhaps some magic mdadm command to add a lost disk and get > it up to speed without a complete sync? If you care about resync speed then look into adding a write intent bitmap to your configuration; otherwise, look into the --assume-clean option to recreate the array. Quoting from the man page: --assume-clean Tell mdadm that the array pre-existed and is known to be clean. It can be useful when trying to recover from a major failure as you can be sure that no data will be affected unless you actually write to the array. It can also be used when creating a RAID1 or RAID10 if you want to avoid the initial resync, however this practice, while normally safe, is not recommended. Use this only if you really know what you are doing. -- Dan