From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luca Berra Subject: Re: RAID 1 resync with both members good. Date: Fri, 8 May 2009 08:07:33 +0200 Message-ID: <20090508060733.GA7759@maude.comedia.it> References: <3D76E016F4A2A749A1EB1A3FD83E22BC02783863@uk-email.terastack.bluearc.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Fri, May 08, 2009 at 10:32:01AM +1000, NeilBrown wrote: >On Thu, May 7, 2009 6:08 pm, Simon Jackson wrote: >> Could someone help me understand why I am seeing the following >> behaviour? >> >> We use a pair of disks with 3 RAID1 partitions inside an appliance >> system. >> >> During testing we have seen some instances of the RAID devices resyncing >> even though both members are marked as good in the output of >> /proc/mdstat. > >That is exactly as expectedc. >If one of the devices had failed and was being replaced by a spare, you >would see "recovery" not "resync". > >Resync happens after an unclean shutdown. >In that case, both drives have good data, but they might not be the same. >The resync makes sure that all copies have exactly the same data. > >So you there must have been an unclean shutdown before the most recent >restart. or a stupid udev rule that gets incremental assembly wrong L. -- Luca Berra -- bluca@comedia.it Communication Media & Services S.r.l. /"\ \ / ASCII RIBBON CAMPAIGN X AGAINST HTML MAIL / \