Re: [Qemu-devel] [PATCH v5 0/5] Geometry and blocksize detection for backing devices.

[Ekaterina Tumanova]

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.