Unable to boot from SCSI disk

Unable to boot from SCSI disk

[Daniel Guillermo Bareiro]

Hi all!

I'm trying libvirt and virt-manager and I found that if I install a
virtual machine with SCSI disks, the installation is done without
problems but when it boots, it is unable to boot from these disks. If I
use bus=sata or bus=virtio, this problem does not happen.

I also tried installing a virtual machine without using virt-install or
virt-manager. Again, no problems at the time of installation, but it is
unable to boot. The only way that gives no problems during the boot is
using the deprectad option ",boot=on".

Could this have to do with a bug in KVM?

I'm using Debian GNU/Linux Wheezy with the following package versions:

Linux:         3.2.41-2+deb7u2
qemu-kvm:      1.1.2+dfsg-6
libvirt-bin:   0.9.12-11
virtinst:      0.600.1-3
virt-manager:  0.9.1-4



Thanks in advance for your reply.

Regards,
Daniel

Re: Unable to boot from SCSI disk

[Paolo Bonzini]

Il 27/05/2013 22:53, Daniel Guillermo Bareiro ha scritto:
> Hi all!
> 
> I'm trying libvirt and virt-manager and I found that if I install a
> virtual machine with SCSI disks, the installation is done without
> problems but when it boots, it is unable to boot from these disks. If I
> use bus=sata or bus=virtio, this problem does not happen.

The default SCSI controller is buggy.  Try using a newer model if
available on your qemu-kvm version, for example virtio-scsi (CCing the
Debian maintainer).

What is the version of SeaBIOS?

Paolo

> I also tried installing a virtual machine without using virt-install or
> virt-manager. Again, no problems at the time of installation, but it is
> unable to boot. The only way that gives no problems during the boot is
> using the deprectad option ",boot=on".
> 
> Could this have to do with a bug in KVM?
> 
> I'm using Debian GNU/Linux Wheezy with the following package versions:
> 
> Linux:         3.2.41-2+deb7u2
> qemu-kvm:      1.1.2+dfsg-6
> libvirt-bin:   0.9.12-11
> virtinst:      0.600.1-3
> virt-manager:  0.9.1-4
> 
> 
> 
> Thanks in advance for your reply.
> 
> Regards,
> Daniel
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Re: Unable to boot from SCSI disk

[Michael Tokarev]

28.05.2013 00:59, Paolo Bonzini wrote:

Thank you Paolo for forwarding this email to me.

> Il 27/05/2013 22:53, Daniel Guillermo Bareiro ha scritto:
>> Hi all!
>>
>> I'm trying libvirt and virt-manager and I found that if I install a
>> virtual machine with SCSI disks, the installation is done without
>> problems but when it boots, it is unable to boot from these disks. If I
>> use bus=sata or bus=virtio, this problem does not happen.
> 
> The default SCSI controller is buggy.  Try using a newer model if
> available on your qemu-kvm version, for example virtio-scsi (CCing the
> Debian maintainer).

Well, it isn't really that lsi emulation is _that_ buggy.  It is
enough for some stuff.  But..

> What is the version of SeaBIOS?

but  it is wheezy, which ships with seabios 1.7.0, which does not
have scsi boot support.  So in order to boot from scsi, you have
to use old ,boot=on device property, which has been forward-ported
from older qemu-kvm version to 1.1 version used on debian, because
it was the only way at that time to boot from an scsi disk without
resorting to using proprietary firmware.

So, boot=on as the drive property should do the trick.  But I'm not
sure it is supported under libvirt.

BTW, why are you installing stuff on scsi?  Is there some particular
reason for that?

Thanks,

/mjt

Re: Unable to boot from SCSI disk

[Michael Tokarev]

28.05.2013 01:25, Michael Tokarev wrote:
[]
> but  it is wheezy, which ships with seabios 1.7.0, which does not
> have scsi boot support.  So in order to boot from scsi, you have
> to use old ,boot=on device property, which has been forward-ported
> from older qemu-kvm version to 1.1 version used on debian, because
> it was the only way at that time to boot from an scsi disk without
> resorting to using proprietary firmware.
> 
> So, boot=on as the drive property should do the trick.  But I'm not
> sure it is supported under libvirt.

A small but maybe important followup.  In unstable (and testing)
version of debian, there is currently a more recent version of
seabios (based on 1.7.2.x), which is able to boot from an scsi
device just fine, and is compatible with qemu[-kvm] 1.1.  You
may try installing that one (just the seabios, nothing more,
it does not have any dependencies whatsoever) and things should
work in regular way.  I'll prepare backports of all stuff in
the very near future.

> BTW, why are you installing stuff on scsi?  Is there some particular
> reason for that?

This question is interesting still.

Thanks,

/mjt

Re: Unable to boot from SCSI disk

[Paolo Bonzini]

Il 27/05/2013 23:25, Michael Tokarev ha scritto:
> 28.05.2013 00:59, Paolo Bonzini wrote:
> 
> Thank you Paolo for forwarding this email to me.
> 
>> Il 27/05/2013 22:53, Daniel Guillermo Bareiro ha scritto:
>>> Hi all!
>>>
>>> I'm trying libvirt and virt-manager and I found that if I install a
>>> virtual machine with SCSI disks, the installation is done without
>>> problems but when it boots, it is unable to boot from these disks. If I
>>> use bus=sata or bus=virtio, this problem does not happen.
>>
>> The default SCSI controller is buggy.  Try using a newer model if
>> available on your qemu-kvm version, for example virtio-scsi (CCing the
>> Debian maintainer).
> 
> Well, it isn't really that lsi emulation is _that_ buggy.  It is
> enough for some stuff.  But..
> 
>> What is the version of SeaBIOS?
> 
> but  it is wheezy, which ships with seabios 1.7.0, which does not
> have scsi boot support.  So in order to boot from scsi, you have
> to use old ,boot=on device property, which has been forward-ported
> from older qemu-kvm version to 1.1 version used on debian, because
> it was the only way at that time to boot from an scsi disk without
> resorting to using proprietary firmware.

Why don't you forward port the SCSI boot patches?

> So, boot=on as the drive property should do the trick.  But I'm not
> sure it is supported under libvirt.

No, it's not.

Paolo

Re: Unable to boot from SCSI disk

[Michael Tokarev]

28.05.2013 12:55, Paolo Bonzini wrote:
> Il 27/05/2013 23:25, Michael Tokarev ha scritto:
[]
>> but  it is wheezy, which ships with seabios 1.7.0, which does not
>> have scsi boot support.  So in order to boot from scsi, you have
>> to use old ,boot=on device property, which has been forward-ported
>> from older qemu-kvm version to 1.1 version used on debian, because
>> it was the only way at that time to boot from an scsi disk without
>> resorting to using proprietary firmware.
> 
> Why don't you forward port the SCSI boot patches?

That'd be back-porting, not forward-porting.

Anyway, in Debian we use a bit different approach usually.  Namely,
instead of backporting lots of stuff resulting in a BigMess(tm),
we provide more recent upstream versions of the software but
compiled for previous (stable) debian release.  This mechanism
is named "debian backports".

The stable release itself does not receive any large feature
updates.  It receives bugfixes, but only important ones.

Besides, this scsi stuff doesn't really matter much -- it
helps in some very rare situations (for example, sometimes
this way it's easier to migrate from vmware to qemu), but
that's about it.  So I don't consider doing backports
especially for scsi.  If the new version backported to
debian _also_ fixes scsi issues, that's just a side-effect.

Thanks,

/mjt

Re: Unable to boot from SCSI disk

[Daniel Guillermo Bareiro]

On Tuesday, 28 May 2013 11:07:25 +0400,
Michael Tokarev wrote:

> A small but maybe important followup.  In unstable (and testing)
> version of debian, there is currently a more recent version of seabios
> (based on 1.7.2.x), which is able to boot from an scsi device just
> fine, and is compatible with qemu[-kvm] 1.1.  You may try installing
> that one (just the seabios, nothing more, it does not have any
> dependencies whatsoever) and things should work in regular way.  I'll
> prepare backports of all stuff in the very near future.

Thank you very much for your effort.

> > BTW, why are you installing stuff on scsi?  Is there some particular
> > reason for that?

> This question is interesting still.

It was not really a necessity. I was just doing my first tests with
libvirt and I came across this problem. Then I started to lose level to
identify where the problem was: virt-manager, libvirt or qemu-[kvm]. And
it seemed like a good idea to comment it on the list.


Thanks for your reply.


Regards,
Daniel

Re: Unable to boot from SCSI disk

[Alexandre DERUMIER]

hello,
I can boot on lsi scsi with qemu 1.4 with

-device scsi-hd -drive file=/dev/

but not

-device scsi-block -drive file=/dev/



----- Mail original ----- 

De: "Daniel Guillermo Bareiro" <daniel-listas@gmx.net> 
À: kvm@vger.kernel.org 
Envoyé: Mercredi 29 Mai 2013 13:11:42 
Objet: Re: Unable to boot from SCSI disk 

On Tuesday, 28 May 2013 11:07:25 +0400, 
Michael Tokarev wrote: 

> A small but maybe important followup. In unstable (and testing) 
> version of debian, there is currently a more recent version of seabios 
> (based on 1.7.2.x), which is able to boot from an scsi device just 
> fine, and is compatible with qemu[-kvm] 1.1. You may try installing 
> that one (just the seabios, nothing more, it does not have any 
> dependencies whatsoever) and things should work in regular way. I'll 
> prepare backports of all stuff in the very near future. 

Thank you very much for your effort. 

> > BTW, why are you installing stuff on scsi? Is there some particular 
> > reason for that? 

> This question is interesting still. 

It was not really a necessity. I was just doing my first tests with 
libvirt and I came across this problem. Then I started to lose level to 
identify where the problem was: virt-manager, libvirt or qemu-[kvm]. And 
it seemed like a good idea to comment it on the list. 


Thanks for your reply. 


Regards, 
Daniel 
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