[CentOS-virt] CentOS 6 Xen virt* issues

Tue Sep 29 15:01:50 UTC 2015
George Dunlap <dunlapg at umich.edu>

On Tue, Sep 29, 2015 at 4:00 PM, Johnny Hughes <johnny at centos.org> wrote:
> On 09/29/2015 07:55 AM, Pasi Kärkkäinen wrote:
>> On Tue, Sep 29, 2015 at 12:37:25PM +0100, George Dunlap wrote:
>>> On Sat, Sep 26, 2015 at 9:29 PM, Pasi Kärkkäinen <pasik at iki.fi> wrote:
>>>> On Sat, Sep 26, 2015 at 09:04:23PM +0300, Pasi Kärkkäinen wrote:
>>>>> Hello,
>>>>> I just upgraded some of my el6xen boxes to latest CentOS 6.7, Xen 4.4.3 and dom0 3.18.17 rpms, and noticed these new problems:
>>>> And third issue aswell:
>>>> 3) Creating an HVM guest using virt-manager with file-based storage uses loopback-mount, not blktap
>>>> When I manually create a new Xen HVM guest using virt-manager, and choose file-based image for storage of the VM, it seems to be set up to use file: backend/driver with loopback-mounted image file:
>>>>     <disk type='file' device='disk'>
>>>>       <driver name='file'/>
>>>>       <source file='/var/lib/libvirt/images/testvm2.img'/>
>>>>       <backingStore/>
>>>>       <target dev='hda' bus='ide'/>
>>>>     </disk>
>>>> # losetup -a
>>>> /dev/loop0: [fd00]:1709109 (/var/lib/libvirt/images/testvm2.img)
>>>> With earlier versions of rpms similar setup used blktap2 backend.. (and yes, I do have blktap module loaded in dom0 kernel).
>>> I remember having to patch some dependency of virt-manager to give it
>>> the correct default driver name (something like, it got 'tap' but
>>> needed to be 'tap2').  In all likelihood, someone has sussed that
>>> 'tap' doesn't work and just replaced it with 'file'.  Actually, it's
>>> fairly likely if they've updated stuff in CentOS that you're not
>>> getting the re-build virt-manager stuff either -- I may have to respin
>>> that one as well.
>> I think it's specified at least in python-virtinst. See these emails from a few years back about the tap/tap2-issue:
>> https://www.redhat.com/archives/virt-tools-list/2013-June/msg00037.html
>> https://www.redhat.com/archives/virt-tools-list/2013-June/msg00039.html
> This is indeed where it was patched before (as a stand alone program) ..
> have they now rolled that into virt-manager?

I'm guessing updated packages in base have a higher version number
than those in the xen4centos repos.  Anyway, I'll take a look at some