From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ian Campbell <Ian.Campbell@citrix.com>
Subject: Re: Fatal crash on xen4.2 HVM + qemu-xen dm + NFS
Date: Tue, 22 Jan 2013 13:14:22 +0000
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To: Alex Bligh <alex@alex.org.uk>
Cc: Konrad Wilk <konrad.wilk@oracle.com>, Xen Devel <xen-devel@lists.xen.org>, Jan Beulich <JBeulich@suse.com>, Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>
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On Tue, 2013-01-22 at 13:01 +0000, Alex Bligh wrote:
> 
> --On 22 January 2013 10:07:07 +0000 Ian Campbell <Ian.Campbell@citrix.com> 
> wrote:
> 
> > On Mon, 2013-01-21 at 20:37 +0000, Alex Bligh wrote:
> >> This would also explain why Ian might not have seen it (it went in
> >> late and without O_DIRECT we think this crash can't happen).
> >
> > When I saw this sort of thing it was with PV guests and blktap. I have
> > never tried anything like this with an HVM guest so it's not hard to
> > explain why I've never seen it there ;-).
> 
> My knowledge of PV guests is about zero, but I thought they used
> xen_disk.c as well.

In my case they were using blkback, which is the kernel and blktap2
(partially kernel and partially usersapce). There is no qemu component
there.

Also I was using a VHD file

Ian.