From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53392) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YAyGR-0007Ei-IS for qemu-devel@nongnu.org; Tue, 13 Jan 2015 04:59:56 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YAyGO-0000Wo-6Y for qemu-devel@nongnu.org; Tue, 13 Jan 2015 04:59:55 -0500 Received: from e06smtp16.uk.ibm.com ([195.75.94.112]:48684) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YAyGN-0000Wc-TR for qemu-devel@nongnu.org; Tue, 13 Jan 2015 04:59:52 -0500 Received: from /spool/local by e06smtp16.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 13 Jan 2015 09:59:49 -0000 Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id 9B49217D8059 for ; Tue, 13 Jan 2015 10:00:23 +0000 (GMT) Received: from d06av11.portsmouth.uk.ibm.com (d06av11.portsmouth.uk.ibm.com [9.149.37.252]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t0D9xjpV44237000 for ; Tue, 13 Jan 2015 09:59:45 GMT Received: from d06av11.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av11.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t0D9xjWx017012 for ; Tue, 13 Jan 2015 02:59:45 -0700 Message-ID: <54B4EC8F.2030408@linux.vnet.ibm.com> Date: Tue, 13 Jan 2015 12:59:43 +0300 From: Ekaterina Tumanova MIME-Version: 1.0 References: <1418901484-12988-1-git-send-email-tumanova@linux.vnet.ibm.com> <20150102113001.GB10823@stefanha-thinkpad.redhat.com> In-Reply-To: <20150102113001.GB10823@stefanha-thinkpad.redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v5 0/5] Geometry and blocksize detection for backing devices. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: kwolf@redhat.com, thuth@linux.vnet.ibm.com, dahi@linux.vnet.ibm.com, armbru@redhat.com, Public KVM Mailing List , mihajlov@linux.vnet.ibm.com, borntraeger@de.ibm.com, stefanha@redhat.com, cornelia.huck@de.ibm.com, pbonzini@redhat.com On 01/02/2015 02:30 PM, Stefan Hajnoczi wrote: > On Thu, Dec 18, 2014 at 12:17:59PM +0100, Ekaterina Tumanova wrote: >> Updates v4 -> v5: >> >> Minor Updates according the last review from Markus: >> 1. update commit message for patch 2 >> 2. fix comment typos >> 3. fix check_for_dasd to return -1 instead of -ENOTSUP >> >> Thanks, >> Kate. >> >> --------------------------------------------------------------- >> Patchset Description (didn't change): >> >> Proper geometry and blocksize information is vital for support of >> DASD/ECKD drives in Linux guests. Otherwise things will fail in >> certain cases. >> >> The existing geometry and blocksize qemu defaults have no sense >> for DASD drives (hd_geometry_guess detection and 512 for sizes). >> Setting this information manually in XML file is far from user-friendly, >> as the admin has to manually look up the properties of the >> host disks and then modify the guest definition accordingly. > > What is the expected behavior when you dd the disk image from the DASD > to a raw image file on an NFS file system on the host? > > It seems you'd lose the geometry detection and the disk image could be > unusable from inside the guest. > This patch set doesn't change the handling of the images, dd'ed from DASDs. Please refer to Christian's reply for details. Thanks a lot for you review! Kate.