Re: [Fedora-xen] Goodbye Xen on RH/Fedora?

[Ján ONDREJ (SAL)]

On Wed, Jan 21, 2009 at 12:19:31PM +0000, Richard W.M. Jones wrote:
>  On Wed, Jan 21, 2009 at 01:12:52PM +0100, Jan ONDREJ (SAL) wrote:
>  
>  You have to tell the host to give the guest a virtio network card -
>  change the NIC <model type='virtio'/> as described here: 
Many thanks. Works well.

>  http://libvirt.org/formatdomain.html#elementsNICS 
There is nothing interesant on this URL. Part elementsNICS is not found,
but also thanks.

On Wed, Jan 21, 2009 at 01:23:06PM +0100, Emre Erenoglu wrote:
>  you need to read the KVM virtio wiki pages, you need to disable that
> 8139
>  emulated card driver (blacklist), then change some line in guest
>  configuration file, and probe virtio driver at boot.
>  
>  http://wiki.libvirt.org/page/Virtio
>  
>
> http://kvm.qumranet.com/kvmwiki?action=fullsearch&context=180&val...
>  
>  find /lib/modules | grep virtio   will give you the list of modules (if they
>  are compiled as modules)
>  
>  You also need to have a recent kernel such as 2.6.25 which has built-in
>  virtio support. 
Thanks. I have it.

virtio_net works well, but I have trouble to boot from virtio_blk.

I can add second disk as virto block device, but I can't boot from first
disk. When using sedond disk, everything works well. When booting via grub,
this is on console:

input: ImExPS/2 Generic Explorer Mouse as
/devices/platform/i8042/serio1/input/input3
Setting up hotplug.
Creating block device nodes.
Creating character device nodes.
Loading pata_acpi module
Loading ata_generic module
Loading virtio_blk module
Creating root device.
Mounting root filesystem.
mount: error mounting /dev/root on /sysroot as ext3: No such file or
directory
Setting up hotplug.
Creating block device nodes.
Creating character device nodes.
Loading pata_acpi module
Loading ata_generic module
Loading virtio_blk module
Creating root device.
Mounting root filesystem.
mount: error mounting /dev/root on /sysroot as ext3: No such file or
directory

I am using UUID in GRUB, my initrd has been regenerated with virtio_blk
module. I think, nash can't create /dev/vda* devices or something similar.
Any ideas, how to debug this or how to fix this?

			SAL

Goodbye Xen on RH/Fedora?

[Richard W.M. Jones]

On Wed, Jan 21, 2009 at 02:28:36PM +0100, Jan ONDREJ (SAL) wrote:
>  virtio_net works well, but I have trouble to boot from virtio_blk.
>  
>  I can add second disk as virto block device, but I can't boot from first
>  disk. When using sedond disk, everything works well. When booting via grub,
>  this is on console: 
Upgrading to using virtio_blk is very complicated.  You have to
rebuild initrd, and there's a difficult circular dependency to be
resolved when doing this because you need to be using virtio_blk in
order for mkinitrd to believe that you need it, although possibly
mkinitrd supports some command line argument to override this.  I
actually gave up at this point.

For newly installed guests, recent anaconda just works everything out
for you and puts the correct drivers into initrd.

Rich.

-- 
Richard Jones, Emerging Technologies, Red Hat  http://et.redhat.com/~rjones
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.
http://et.redhat.com/~rjones/virt-df/

Goodbye Xen on RH/Fedora?

[Daniel P. Berrange]

On Wed, Jan 21, 2009 at 01:45:52PM +0000, Richard W.M. Jones wrote:
>  On Wed, Jan 21, 2009 at 02:28:36PM +0100, Jan ONDREJ (SAL) wrote:
>  > virtio_net works well, but I have trouble to boot from virtio_blk.
>  > 
>  > I can add second disk as virto block device, but I can't boot from first
>  > disk. When using sedond disk, everything works well. When booting via grub,
>  > this is on console:
>  
>  Upgrading to using virtio_blk is very complicated.  You have to
>  rebuild initrd, and there's a difficult circular dependency to be
>  resolved when doing this because you need to be using virtio_blk in
>  order for mkinitrd to believe that you need it, although possibly
>  mkinitrd supports some command line argument to override this.  I
>  actually gave up at this point. 
Just tell it to include virtio_blk module explicitly eg

    mkinitrd --with=virtio_blk  .....other option...

Daniel
-- 
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Goodbye Xen on RH/Fedora?

[Gerd Hoffmann]

  Hi,

>  Just tell it to include virtio_blk module explicitly eg
>  
>      mkinitrd --with=virtio_blk  .....other option... 
virtio_pci too (which is probably the issue in this case, as the
reporter sayed virtio_blk is included already).

cheers,
  Gerd

Switching from IDE to virtio_blk [qas Re: Goodbye Xen on RH/Fedora?]

[Mark McLoughlin]

(This is all getting offtopic for fedora-xen, we should really move to
fedora-virt)

On Wed, 2009-01-21 at 14:28 +0100, Jan ONDREJ (SAL) wrote:
>   virtio_net works well, but I have trouble to boot from virtio_blk.
>  
>  I can add second disk as virto block device, but I can't boot from
>  first disk. 
When switching from IDE to virtio, you need to first build a new initrd
in the guest with e.g.:

  $> mkinitrd --with virtio_pci --with virtio_blk -f /boot/initrd-$(kernelversion)
$(kernelversion)

You only need to do this once. After that, if a new kernel is installed
while you're booted off a virtio disk, then mkinitrd will include the
modules automatically.

Cheers,
Mark.

Switching from IDE to virtio_blk [qas Re: Goodbye Xen on RH/Fedora?]

[Emre Erenoglu]

On Wed, Jan 21, 2009 at 2:48 PM, Mark McLoughlin <markmc(a)redhat.com&gt; wrote:

>  (This is all getting offtopic for fedora-xen, we should really move
> to
>  fedora-virt)
>
>  On Wed, 2009-01-21 at 14:28 +0100, Jan ONDREJ (SAL) wrote:
>  >  virtio_net works well, but I have trouble to boot from virtio_blk.
>  >
>  > I can add second disk as virto block device, but I can't boot from
>  > first disk.
>
>  When switching from IDE to virtio, you need to first build a new initrd
>  in the guest with e.g.:
>
>   $> mkinitrd --with virtio_pci --with virtio_blk -f
>  /boot/initrd-$(kernelversion) $(kernelversion)
>
>  You only need to do this once. After that, if a new kernel is installed
>  while you're booted off a virtio disk, then mkinitrd will include the
>  modules automatically. 

You will also need to specify /dev/vdX on the kernel  root= line and make
sure your init script inside your initrd triggers the virtio drivers at boot
so that the /dev/vdX are created.

-- 
Emre

Switching from IDE to virtio_blk [qas Re: Goodbye Xen on RH/Fedora?]

[Richard W.M. Jones]

On Wed, Jan 21, 2009 at 03:06:43PM +0100, Emre Erenoglu wrote:
>  On Wed, Jan 21, 2009 at 2:48 PM, Mark McLoughlin
> <markmc(a)redhat.com&gt; wrote:
>  
>  > (This is all getting offtopic for fedora-xen, we should really move to
>  > fedora-virt)
>  >
>  > On Wed, 2009-01-21 at 14:28 +0100, Jan ONDREJ (SAL) wrote:
>  > >  virtio_net works well, but I have trouble to boot from virtio_blk.
>  > >
>  > > I can add second disk as virto block device, but I can't boot from
>  > > first disk.
>  >
>  > When switching from IDE to virtio, you need to first build a new initrd
>  > in the guest with e.g.:
>  >
>  >  $> mkinitrd --with virtio_pci --with virtio_blk -f
>  > /boot/initrd-$(kernelversion) $(kernelversion)
>  >
>  > You only need to do this once. After that, if a new kernel is installed
>  > while you're booted off a virtio disk, then mkinitrd will include the
>  > modules automatically.
>  
>  
>  You will also need to specify /dev/vdX on the kernel  root= line and make
>  sure your init script inside your initrd triggers the virtio drivers at boot
>  so that the /dev/vdX are created. 
Yes I have to agree with Emre here - I don't think it's as simple as
just rebuilding mkinitrd.  I got that far but gave up later on.

/me checks notes ...

Yup, I got as far as working out that you would have to edit fstab and
possibly /boot/grub/device.map and /boot/grub/menu.lst, before giving
up.

If anyone would like to fill in the wiki page here on the subject:

  http://wiki.libvirt.org/page/Virtio

I'd like to reiterate that _none_ of this complexity is required when
installing a new guest.  Anaconda sets up everything for you.

Rich.

-- 
Richard Jones, Emerging Technologies, Red Hat  http://et.redhat.com/~rjones
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.
http://et.redhat.com/~rjones/virt-df/

Switching from IDE to virtio_blk [qas Re: Goodbye Xen on RH/Fedora?]

[Emre Erenoglu]

On Wed, Jan 21, 2009 at 3:45 PM, Richard W.M. Jones <rjones(a)redhat.com&gt;wrote:

>  On Wed, Jan 21, 2009 at 03:06:43PM +0100, Emre Erenoglu wrote:
>  > On Wed, Jan 21, 2009 at 2:48 PM, Mark McLoughlin <markmc(a)redhat.com&gt;
>  wrote:
>  >
>  > > (This is all getting offtopic for fedora-xen, we should really move to
>  > > fedora-virt)
>  > >
>  > > On Wed, 2009-01-21 at 14:28 +0100, Jan ONDREJ (SAL) wrote:
>  > > >  virtio_net works well, but I have trouble to boot from virtio_blk.
>  > > >
>  > > > I can add second disk as virto block device, but I can't boot from
>  > > > first disk.
>  > >
>  > > When switching from IDE to virtio, you need to first build a new initrd
>  > > in the guest with e.g.:
>  > >
>  > >  $> mkinitrd --with virtio_pci --with virtio_blk -f
>  > > /boot/initrd-$(kernelversion) $(kernelversion)
>  > >
>  > > You only need to do this once. After that, if a new kernel is installed
>  > > while you're booted off a virtio disk, then mkinitrd will include the
>  > > modules automatically.
>  >
>  >
>  > You will also need to specify /dev/vdX on the kernel  root= line and make
>  > sure your init script inside your initrd triggers the virtio drivers at
>  boot
>  > so that the /dev/vdX are created.
>
>  Yes I have to agree with Emre here - I don't think it's as simple as
>  just rebuilding mkinitrd.  I got that far but gave up later on. 

Well what I did was that I created a special initramfs, with virtio-net and
virtio-blk drivers, as well as all of their dependencies (virtio-pci,
virti-baloon and possibly one more), edited the init script going inside the
initrd image so that it triggers the virtio drivers, then booted up on that
ROOT filesystem using the kernel command line.

on system side, it's better to edit fstab but root is anyway mounted.

You may need to boot to shell at your initrd to see what's going on, or
probe by hand to see the devices are created etc.

You also need to use the correct guest configuration file so that
virtio-type devices are created instead of emulated ones.

-- 
Emre

Switching from IDE to virtio_blk [qas Re: Goodbye Xen on RH/Fedora?]

[Mark McLoughlin]

On Wed, 2009-01-21 at 14:45 +0000, Richard W.M. Jones wrote:
>  On Wed, Jan 21, 2009 at 03:06:43PM +0100, Emre Erenoglu wrote:
>  > On Wed, Jan 21, 2009 at 2:48 PM, Mark McLoughlin <markmc(a)redhat.com&gt; wrote:
>  > 
>  > > (This is all getting offtopic for fedora-xen, we should really move to
>  > > fedora-virt)
>  > >
>  > > On Wed, 2009-01-21 at 14:28 +0100, Jan ONDREJ (SAL) wrote:
>  > > >  virtio_net works well, but I have trouble to boot from virtio_blk.
>  > > >
>  > > > I can add second disk as virto block device, but I can't boot from
>  > > > first disk.
>  > >
>  > > When switching from IDE to virtio, you need to first build a new initrd
>  > > in the guest with e.g.:
>  > >
>  > >  $> mkinitrd --with virtio_pci --with virtio_blk -f
>  > > /boot/initrd-$(kernelversion) $(kernelversion)
>  > >
>  > > You only need to do this once. After that, if a new kernel is installed
>  > > while you're booted off a virtio disk, then mkinitrd will include the
>  > > modules automatically.
>  > 
>  > 
>  > You will also need to specify /dev/vdX on the kernel  root= line and make
>  > sure your init script inside your initrd triggers the virtio drivers at boot
>  > so that the /dev/vdX are created.
>  
>  Yes I have to agree with Emre here - I don't think it's as simple as
>  just rebuilding mkinitrd.  I got that far but gave up later on.
>  
>  /me checks notes ...
>  
>  Yup, I got as far as working out that you would have to edit fstab and
>  possibly /boot/grub/device.map and /boot/grub/menu.lst, before giving
>  up. 
Could this have been an x86_64 Fedora 9 xen guest? If so, you probably
hit a nasty special case - the F9 x86_64 xen kernel didn't have support
for running 32 bit binaries like grub, so the bootloader would never
have been installed into the MBR. That works fine for pygrub, but not
with KVM's real BIOS.

>  If anyone would like to fill in the wiki page here on the subject:
>  
>    http://wiki.libvirt.org/page/Virtio 
Okay, added some bits.

Cheers,
Mark.

Switching from IDE to virtio_blk [qas Re: Goodbye Xen on RH/Fedora?]

[Dustin Henning]

	It is probably worth noting that if someone were to run a kernel
update with a package manager after getting this working (using information
from later posts in this thread), they would need to do a manual mkinitrd.
At least that was my experience some time ago when switching from hda to sda
in CentOS, future kernel-xen versions installed via yum tried to boot to hda
and failed.  However, I think I actually recompiled originally, though, as
opposed to adding the new drivers to initrd, so I could be wrong.
	Dustin

-----Original Message-----
From: fedora-xen-bounces(a)redhat.com [mailto:[e-mail]]
On Behalf Of Mark McLoughlin
Sent: Wednesday, January 21, 2009 08:49
To: Jan ONDREJ (SAL)
Cc: Fedora Xen
Subject: Switching from IDE to virtio_blk [qas Re: [Fedora-xen] Goodbye Xen
on RH/Fedora?]

(This is all getting offtopic for fedora-xen, we should really move to
fedora-virt)

On Wed, 2009-01-21 at 14:28 +0100, Jan ONDREJ (SAL) wrote:
>   virtio_net works well, but I have trouble to boot from virtio_blk.
>  
>  I can add second disk as virto block device, but I can't boot from
>  first disk. 
When switching from IDE to virtio, you need to first build a new initrd
in the guest with e.g.:

  $> mkinitrd --with virtio_pci --with virtio_blk -f
/boot/initrd-$(kernelversion) $(kernelversion)

You only need to do this once. After that, if a new kernel is installed
while you're booted off a virtio disk, then mkinitrd will include the
modules automatically.

Cheers,
Mark.

--
Fedora-xen mailing list
Fedora-xen(a)redhat.com
https://www.redhat.com/mailman/listinfo/fedora-xen

Switching from IDE to virtio_blk [qas Re: Goodbye Xen on RH/Fedora?]

[Ján ONDREJ (SAL)]

You missed, that I am migrating not only my packages, but my whole virtual
machine from paravirtualized Xen to paravirt. driver KVM.
This mkinitrd magic is only required for disk driver change (xenblk_front to
virtio_blk).
So it's something different, like your upgrade of CentOS.

	SAL

On Wed, Jan 21, 2009 at 01:47:34PM -0500, Dustin Henning wrote:
>  	It is probably worth noting that if someone were to run a kernel
>  update with a package manager after getting this working (using information
>  from later posts in this thread), they would need to do a manual mkinitrd.
>  At least that was my experience some time ago when switching from hda to sda
>  in CentOS, future kernel-xen versions installed via yum tried to boot to hda
>  and failed.  However, I think I actually recompiled originally, though, as
>  opposed to adding the new drivers to initrd, so I could be wrong.
>  	Dustin
>  
>  -----Original Message-----
>  From: fedora-xen-bounces(a)redhat.com [mailto:[e-mail]]
>  On Behalf Of Mark McLoughlin
>  Sent: Wednesday, January 21, 2009 08:49
>  To: Jan ONDREJ (SAL)
>  Cc: Fedora Xen
>  Subject: Switching from IDE to virtio_blk [qas Re: [Fedora-xen] Goodbye Xen
>  on RH/Fedora?]
>  
>  (This is all getting offtopic for fedora-xen, we should really move to
>  fedora-virt)
>  
>  On Wed, 2009-01-21 at 14:28 +0100, Jan ONDREJ (SAL) wrote:
>  >  virtio_net works well, but I have trouble to boot from virtio_blk.
>  > 
>  > I can add second disk as virto block device, but I can't boot from
>  > first disk.
>  
>  When switching from IDE to virtio, you need to first build a new initrd
>  in the guest with e.g.:
>  
>    $> mkinitrd --with virtio_pci --with virtio_blk -f
>  /boot/initrd-$(kernelversion) $(kernelversion)
>  
>  You only need to do this once. After that, if a new kernel is installed
>  while you're booted off a virtio disk, then mkinitrd will include the
>  modules automatically.
>  
>  Cheers,
>  Mark.
>  
>  --
>  Fedora-xen mailing list
>  Fedora-xen(a)redhat.com
>  https://www.redhat.com/mailman/listinfo/fedora-xen
>

Switching from IDE to virtio_blk [qas Re: Goodbye Xen on RH/Fedora?]

[Mark McLoughlin]

On Wed, 2009-01-21 at 13:47 -0500, Dustin Henning wrote:
>   It is probably worth noting that if someone were to run a kernel
>  update with a package manager after getting this working (using
>  information
>  from later posts in this thread), they would need to do a manual
>  mkinitrd. 
No. If you boot off /dev/vda and update the kernel, mkinitrd will build
an initrd containing the virtio modules.

Cheers,
Mark.

Switching from IDE to virtio_blk [qas Re: Goodbye Xen on RH/Fedora?]

[Emre Erenoglu]

On Thu, Jan 22, 2009 at 10:20 AM, Mark McLoughlin <markmc(a)redhat.com&gt; wrote:

>  On Wed, 2009-01-21 at 13:47 -0500, Dustin Henning wrote:
>  >  It is probably worth noting that if someone were to run a kernel
>  > update with a package manager after getting this working (using
>  > information
>  > from later posts in this thread), they would need to do a manual
>  > mkinitrd.
>
>  No. If you boot off /dev/vda and update the kernel, mkinitrd will build
>  an initrd containing the virtio modules. 

Well, that may depend if you use mkinitrd or mkinitramfs, and your
distribution mkinitramfs or mkinitrd may not be checking which device type
he's working on.

Emre

Switching from IDE to virtio_blk [qas Re: Goodbye Xen on RH/Fedora?]

[Mark McLoughlin]

On Thu, 2009-01-22 at 11:06 +0100, Emre Erenoglu wrote:
>   
>  On Thu, Jan 22, 2009 at 10:20 AM, Mark McLoughlin <markmc(a)redhat.com&gt;
>  wrote:
>          On Wed, 2009-01-21 at 13:47 -0500, Dustin Henning wrote:
>          >  It is probably worth noting that if someone were to run a
>          kernel
>          > update with a package manager after getting this working
>          (using
>          > information
>          > from later posts in this thread), they would need to do a
>          manual
>          > mkinitrd.
>          
>          
>          No. If you boot off /dev/vda and update the kernel, mkinitrd
>          will build
>          an initrd containing the virtio modules.
>  
>  
>  Well, that may depend if you use mkinitrd or mkinitramfs, and your
>  distribution mkinitramfs or mkinitrd may not be checking which device
>  type he's working on.  
Yes, since we're on a Fedora mailing list, I'm assuming Fedora
mkinitrd :-)

Cheers,
Mark.

Switching from IDE to virtio_blk [qas Re: Goodbye Xen on RH/Fedora?]

[Ján ONDREJ (SAL)]

On Thu, Jan 22, 2009 at 10:21:50AM +0000, Mark McLoughlin wrote:
>  On Thu, 2009-01-22 at 11:06 +0100, Emre Erenoglu wrote:
>  >  
>  > On Thu, Jan 22, 2009 at 10:20 AM, Mark McLoughlin <markmc(a)redhat.com&gt;
>  > wrote:
>  >         On Wed, 2009-01-21 at 13:47 -0500, Dustin Henning wrote:
>  >         >  It is probably worth noting that if someone were to run a
>  >         kernel
>  >         > update with a package manager after getting this working
>  >         (using
>  >         > information
>  >         > from later posts in this thread), they would need to do a
>  >         manual
>  >         > mkinitrd.
>  >         
>  >         No. If you boot off /dev/vda and update the kernel, mkinitrd
>  >         will build
>  >         an initrd containing the virtio modules.
>  > 
>  > Well, that may depend if you use mkinitrd or mkinitramfs, and your
>  > distribution mkinitramfs or mkinitrd may not be checking which device
>  > type he's working on.  
May be adding virtio disk drivers to initrd files always may help all users.
I don't know, if there is anything, why initrd have to be small.

		SAL