From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: Can't resolve mismatch_count > 0 for a raid 1 array Date: Wed, 08 Apr 2009 17:50:46 -0400 Message-ID: <49DD1C36.1000306@tmr.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Steven Ellis Cc: Linux RAID List-Id: linux-raid.ids Steven Ellis wrote: > I've resolved most of my raid issues by re-housing the affected system > and replacing the motherboard, but across the 3 boards I've tried I > always have an issue with my /dev/md1 array producing mismatch_count > of 128 or 256. > > System is running Centos 5.2 with a Xen Dom0 kernel > > This md1 volume is a pair of 40GB HDs raid1 on an IDE controller which > I them have a bunch of LVM's that are my Xen guests. > > Is there any chance that these mismatch_count values are due to swap > partitions for the Xen guests? That's the cause, and since md code doesn't currently have a clue which copy is "right" it's always a problem if you do something like suspend to disk. You probably don't do that with xen images, but swap and raid1 almost always have a mismatch. -- bill davidsen CTO TMR Associates, Inc "You are disgraced professional losers. And by the way, give us our money back." - Representative Earl Pomeroy, Democrat of North Dakota on the A.I.G. executives who were paid bonuses after a federal bailout.