From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ryan Harper Subject: Re: [REGRESSION][BISECTED] virtio-blk serial attribute causes guest to hang [Was: Re: [PATCH UPDATED 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm] Date: Thu, 9 Sep 2010 13:35:54 -0500 Message-ID: <20100909183554.GK30086@us.ibm.com> References: <20100902032246.GA31484@redhat.com> <20100909152658.GA8118@redhat.com> <20100909154442.GI30086@us.ibm.com> <20100909155726.GA9081@redhat.com> <20100909160324.GJ30086@us.ibm.com> <20100909175537.GA9589@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ryan Harper , Tejun Heo , Mikulas Patocka , dm-devel@redhat.com, Vivek Goyal , john.cooper@redhat.com, rusty@rustcorp.com.au, hch@infradead.org, kvm@vger.kernel.org To: Mike Snitzer Return-path: Received: from e34.co.us.ibm.com ([32.97.110.152]:42706 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751975Ab0IISgd (ORCPT ); Thu, 9 Sep 2010 14:36:33 -0400 Received: from d03relay05.boulder.ibm.com (d03relay05.boulder.ibm.com [9.17.195.107]) by e34.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id o89IRKj6012320 for ; Thu, 9 Sep 2010 12:27:20 -0600 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay05.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o89Ia2j9126460 for ; Thu, 9 Sep 2010 12:36:07 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id o89Ia0Kb001741 for ; Thu, 9 Sep 2010 12:36:02 -0600 Content-Disposition: inline In-Reply-To: <20100909175537.GA9589@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: * Mike Snitzer [2010-09-09 12:56]: > On Thu, Sep 09 2010 at 12:03pm -0400, > Ryan Harper wrote: > > > * Mike Snitzer [2010-09-09 10:58]: > > > > I'm using virtio-blk w/ cache=none for the root device. virtio-blk > > > isn't used for any other devices in the guest. > > > > And you don't have any other disks in the guest (I see just the root and > > the cdrom), the lv stuff is happening against some sort of dummy target? > > Correct. I have used variants of the script I provided against both > scsi-debug devices and iscsi devices in the guest. The script I shared > uses multipath on scsi-debug (ram-based) devices. > > That script causes udev to run its various callouts via multipath and > LVM (both packages, upstream and RHEL6, now use udev). > > I have verified that I no longer get the hang if I switch the root > device from virtio to ide. And in the failing case, do you see: /sys/block/vda/serial attribute in sysfs? -- Ryan Harper Software Engineer; Linux Technology Center IBM Corp., Austin, Tx ryanh@us.ibm.com