libvirt users - Oct 2016 - Re: problem with disk virtio driver

On Wed, Oct 5, 2016 at 4:18 PM, Martin Kletzander <mkletzan@redhat.com>
wrote:
> On Wed, Oct 05, 2016 at 03:00:40PM +0100, Andrei Perietanu wrote:
>
>> Hi Andrea,
>>   Thanks for the reply;
>>   To shed some more light on the matter I performed a few more tests;
each
>> time doing a clean install. I installed ubuntu14.04 as the guest OS,
>> keeping everything else the same.
>> On my custom Linux I've created ubuntu VMs before (using ide
drivers) and
>> it all works file. This time I created the VM using virtio disk drivers
>> and
>>
>
> So switching only the guest OS (keeping the host OS, domain XML and
> everything) works, so how can the problem be anywhere else than the
> guest OS?  You might be, most probably, missing some kernel option.
> What is the difference between the installer and the system installed?
> Are they using the same kernel?  Accessing the same things?
>
> the installation didn't even finish. It reported a disk related error
>> saying it's not being able to read from /dev/vda. I restarted the
>> machine...same error.
>>
>
> You're adding more configurations into the mix, let's skip that and
only
> talk about what you had before, the IDE and ubuntu/your distro.
>
>    Just to make sure that I have not messed anything up, I did the same on
>> the ubuntu host, so installed ubuntu guest on an ubuntu host uding the
>> same
>> guest config xml. This time everything worked fine. So it looks like a
>> problem with the kvm virtio drivers.
>>
>>    I was trying to stay away from updating the qemu package because
adding
>> the package takes a long time (usually, because of missing
dependencies),
>> but I'm not sure I have any other option at this point...
>>
>>
> Are there that many since 1.1.2?  I don't think that much has changed.
> But it should be solvable without updating (plus the update might not
> fix it for you.
>
Let me try and recap what is happening :
On my custom embedded linux, using the same domain config xml, just
changing the disk drivers and/or the iso
    Ubuntu.iso + ide disk drivers -> works
    Ubuntu.iso + virio disk drivers -> does not work; errors when reading
from /dev/vda
    customLinuxOS.iso + virtio drivers -> does not seem to work; kernel
panics and services stop working


On Ubuntu10.04 host, using the same domain config xml as before, just
changing the iso
     Ubuntu.iso + virtio disk drivers -> vorks
     customLinuxOS.iso + virtio drivers -> works

This sounds to me like a problem with kvm virtio drivers (since when using
ide drivers installing ubuntu as a guest works)

If there is anything I'm missing, or you think I should try ..I'm open
to
trying it.

Thanks,
Andrei

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Hi all,
   I have to admit Martin might have been right: I upgraded to qemu 2.6.0
and still I see the same problem with virtio disks on my custom built Linux
box.

I create domain using the previously mentioned domain xml definition and
try to install ubuntu from an iso. Earty on during the installation I get
an error:
The attempt to mount a file system with type ext4 in Virtual disk1,
partition#1 (vda1) at / failed
At this point the installation fails and I have to reboot the domain.

There obviously is something I'm missing since the same works on a ubuntu
host machine but I have no idea what or how to debug it.

Any help is greatly appreciated.

Thanks!


On Wed, Oct 5, 2016 at 5:07 PM, Andrei Perietanu <
andrei.perietanu@klastelecom.com> wrote:
>
>
> On Wed, Oct 5, 2016 at 4:18 PM, Martin Kletzander
<mkletzan@redhat.com>
> wrote:
>
>> On Wed, Oct 05, 2016 at 03:00:40PM +0100, Andrei Perietanu wrote:
>>
>>> Hi Andrea,
>>>   Thanks for the reply;
>>>   To shed some more light on the matter I performed a few more
tests;
>>> each
>>> time doing a clean install. I installed ubuntu14.04 as the guest
OS,
>>> keeping everything else the same.
>>> On my custom Linux I've created ubuntu VMs before (using ide
drivers) and
>>> it all works file. This time I created the VM using virtio disk
drivers
>>> and
>>>
>>
>> So switching only the guest OS (keeping the host OS, domain XML and
>> everything) works, so how can the problem be anywhere else than the
>> guest OS?  You might be, most probably, missing some kernel option.
>> What is the difference between the installer and the system installed?
>> Are they using the same kernel?  Accessing the same things?
>>
>> the installation didn't even finish. It reported a disk related
error
>>> saying it's not being able to read from /dev/vda. I restarted
the
>>> machine...same error.
>>>
>>
>> You're adding more configurations into the mix, let's skip that
and only
>> talk about what you had before, the IDE and ubuntu/your distro.
>>
>>    Just to make sure that I have not messed anything up, I did the same
on
>>> the ubuntu host, so installed ubuntu guest on an ubuntu host uding
the
>>> same
>>> guest config xml. This time everything worked fine. So it looks
like a
>>> problem with the kvm virtio drivers.
>>>
>>>    I was trying to stay away from updating the qemu package because
>>> adding
>>> the package takes a long time (usually, because of missing
dependencies),
>>> but I'm not sure I have any other option at this point...
>>>
>>>
>> Are there that many since 1.1.2?  I don't think that much has
changed.
>> But it should be solvable without updating (plus the update might not
>> fix it for you.
>>
>
> Let me try and recap what is happening :
> On my custom embedded linux, using the same domain config xml, just
> changing the disk drivers and/or the iso
>     Ubuntu.iso + ide disk drivers -> works
>     Ubuntu.iso + virio disk drivers -> does not work; errors when
reading
> from /dev/vda
>     customLinuxOS.iso + virtio drivers -> does not seem to work; kernel
> panics and services stop working
>
>
> On Ubuntu10.04 host, using the same domain config xml as before, just
> changing the iso
>      Ubuntu.iso + virtio disk drivers -> vorks
>      customLinuxOS.iso + virtio drivers -> works
>
> This sounds to me like a problem with kvm virtio drivers (since when using
> ide drivers installing ubuntu as a guest works)
>
> If there is anything I'm missing, or you think I should try ..I'm
open to
> trying it.
>
> Thanks,
> Andrei
>
>
-- 
 

The information transmitted is intended only for the person or entity to 
which it is addressed and may contain confidential and/or privileged 
material. Any review, retransmission, dissemination or other use of or 
taking of any action in reliance upon this information by persons or 
entities other than the intended recipient is prohibited. If you receive 
this in error please contact the sender and delete the material from any 
computer immediately. It is the policy of Klas  Limited to disavow the 
sending of offensive material and should you consider that the material 
contained in the message is offensive you should contact the sender 
immediately and also your I.T. Manager.

Klas Telecom Inc., a Virginia Corporation with offices at 1101 30th St. NW, 
Washington, DC 20007.

Klas Limited (Company Number 163303) trading as Klas Telecom, an Irish 
Limited Liability Company, with its registered office at Fourth Floor, One 
Kilmainham Square, Inchicore Road, Kilmainham, Dublin 8, Ireland.

On Thu, Oct 13, 2016 at 01:47:08PM +0100, Andrei Perietanu
wrote:
>Hi all,
>   I have to admit Martin might have been right: I upgraded to qemu 2.6.0
>and still I see the same problem with virtio disks on my custom built Linux
>box.
>
>I create domain using the previously mentioned domain xml definition and
>try to install ubuntu from an iso. Earty on during the installation I get
>an error:
>The attempt to mount a file system with type ext4 in Virtual disk1,
>partition#1 (vda1) at / failed
>At this point the installation fails and I have to reboot the domain.
>
>There obviously is something I'm missing since the same works on a
ubuntu
>host machine but I have no idea what or how to debug it.
>
>Any help is greatly appreciated.
>
>Thanks!
Yes, I think this is a problem with kvm/virtio then, yes.  But
unfortunately it's highly improbable that you'd get much help on kernel
issues from libvir-list.  Maybe qemu people can help.  But I doubt the
problem is in libvirt.  Sorry.