Xen Dom0 and Fedora

[Steven Haigh]

I'm just writing to try and gauge the progress of Xen in newer Fedora 
 releases.

I spent a bit of the night trying to get F14 to work as a Xen Dom0 
 using the included 4.0.1 hypervisor - that is until I realised that Dom0 
 is not available in F14!

So I've rolled everything back to CentOS 5.5 & Xen 3.2.3 via the Gitco 
 repo and its up and running again. Everything I managed to find says 
 *maybe* in F15? Anyone in the know able to help out?

[Bruno Wolff III]

On Tue, Dec 28, 2010 at 07:36:08 +1100,
  Steven Haigh  wrote:
> So I've rolled everything back to CentOS 5.5 & Xen 3.2.3 via the Gitco 
>  repo and its up and running again. Everything I managed to find says 
>  *maybe* in F15? Anyone in the know able to help out?

The 2.6.37 kernel has some xen changes. I don't know if they give you
everything you need though. F15 will probably release with 2.6.38.

[Rahul Sundaram]

On 12/28/2010 02:06 AM, Steven Haigh wrote:
> I'm just writing to try and gauge the progress of Xen in newer Fedora 
>  releases.
>
> I spent a bit of the night trying to get F14 to work as a Xen Dom0 
>  using the included 4.0.1 hypervisor - that is until I realised that Dom0 
>  is not available in F14!
>
> So I've rolled everything back to CentOS 5.5 & Xen 3.2.3 via the Gitco 
>  repo and its up and running again. Everything I managed to find says 
>  *maybe* in F15? Anyone in the know able to help out?

http://fedoraproject.org/wiki/Features/XenPvopsDom0

http://lists.fedoraproject.org/pipermail/xen/2010-November/005205.html

Rahul

[Steven Haigh]

On 28/12/2010 5:05 PM, Rahul Sundaram wrote:
> On 12/28/2010 02:06 AM, Steven Haigh wrote:
> > I'm just writing to try and gauge the progress of Xen in newer Fedora
> >   releases.
> >
> > I spent a bit of the night trying to get F14 to work as a Xen Dom0
> >   using the included 4.0.1 hypervisor - that is until I realised that Dom0
> >   is not available in F14!
> >
> > So I've rolled everything back to CentOS 5.5&  Xen 3.2.3 via the Gitco
> >   repo and its up and running again. Everything I managed to find says
> >   *maybe* in F15? Anyone in the know able to help out?
>
> http://fedoraproject.org/wiki/Features/XenPvopsDom0
>
> http://lists.fedoraproject.org/pipermail/xen/2010-November/005205.html
>
> Rahul

Yeah - I saw these but this made me wonder:

Targeted release: Fedora 15
     Last updated: 2010-10-29
     Percentage of completion: 0%

Everything I've read points to waiting for the magic to happen in the 
kernel - however I'm not sure if that is a case of everyone else waiting 
for someone else to do something, or some other reason...

[Rahul Sundaram]

Everything I've read points to waiting for the magic to happen in the
kernel - however I'm not sure if that is a case of everyone else waiting
for someone else to do something, or some other reason...

If you follow the Fedora Xen thread further along, you will get the answer.
Essentially domu is queued to be merged in 2.6.37.  Rest of the smaller
changes can be cherry picked if necessary.

http://wiki.xensource.com/xenwiki/XenParavirtOps

Jeremy is working on this upstream.  You will have to follow LKML to see
that.

If you want to try now

http://fedorapeople.org/~myoung/dom0/http://fedorapeople.org/%7Emyoung/dom0/

Rahul

[Steven Haigh]

On 28/12/2010 10:30 PM, Rahul Sundaram wrote:
> > Everything I've read points to waiting for the magic to happen in the
> > kernel - however I'm not sure if that is a case of everyone else waiting
> > for someone else to do something, or some other reason...
>
> If you follow the Fedora Xen thread further along, you will get the
> answer.  Essentially domu is queued to be merged in 2.6.37.  Rest of the
> smaller changes can be cherry picked if necessary.
>
> http://wiki.xensource.com/xenwiki/XenParavirtOps
>
> Jeremy is working on this upstream.  You will have to follow LKML to see
> that.

Ahhh - I hadn't come across anything on LKML as yet - I'll have a hunt 
through today...
> If you want to try now
>
> http://fedorapeople.org/~myoung/dom0/
> http://fedorapeople.org/%7Emyoung/dom0/

I did try these - but it seems they are only F12 kernels. I did try 
using them anyhow however after loading the hypervisor, the system just 
stopped. I didn't have a chance to hook up serial consoles or anything 
to debug it at that stage. Might do it with a spare machine if I get 
time and see whats going on.

[M A Young]

On Wed, 29 Dec 2010, Steven Haigh wrote:
> > If you want to try now
> >
> > http://fedorapeople.org/~myoung/dom0/
> > http://fedorapeople.org/%7Emyoung/dom0/
>
> I did try these - but it seems they are only F12 kernels. I did try using 
> them anyhow however after loading the hypervisor, the system just stopped.

It should still work on F13 and F14 (though not on rawhide because it 
isn't compatible with systemd). What does your grub.conf look like? The 
should be something along the lines of
Title something
    kernel /path/xen.gz
    module /path/vmlinuz..... kernel-options
    module initramfs....

[Steven Haigh]

On 31/12/2010 9:46 AM, M A Young wrote:
> On Wed, 29 Dec 2010, Steven Haigh wrote:
> > > If you want to try now
> > >
> > > http://fedorapeople.org/~myoung/dom0/
> > > http://fedorapeople.org/%7Emyoung/dom0/
> >
> > I did try these - but it seems they are only F12 kernels. I did try using
> > them anyhow however after loading the hypervisor, the system just stopped.
>
> It should still work on F13 and F14 (though not on rawhide because it
> isn't compatible with systemd). What does your grub.conf look like? The
> should be something along the lines of
> Title something
>    kernel /path/xen.gz
>    module /path/vmlinuz..... kernel-options
>    module initramfs....

Sorry for the delay in this - I've rehashed my Xen system with lvm so 
that I can dual boot it between the working CentOS config and the 
experiments with F14 - that way things aren't down until I reinstall 
everything! :)

When I boot the x86_64 kernel from 
http://fedorapeople.org/~myoung/dom0/, the xen hypervisor loads, then I 
just get a black screen. The monitor goes into power savings and all 
seems dead. I can't see any disk activity at all - however pressing 
C-A-D does reboot the machine almost instantly.

My grub.conf entry:
title Fedora (2.6.32.26-174.2.xendom0.fc12.x86_64)
         root (hd1,0)
         kernel /xen.gz cpufreq=xen dom0_mem=512M loglvl=all 
guest_loglvl=all dom0_max_vcpus=4 dom0_vcpus_pin
         module /vmlinuz-2.6.32.26-174.2.xendom0.fc12.x86_64 ro 
root=/dev/mapper/RAID1-xenhost2 rd_LVM_LV=RAID1/xenhost2 
rd_MD_UUID=36de56a8:f0b5a953:26cc0f1b:25854d9c rd_NO_LUKS rd_NO_DM 
LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=us rhgb quiet
         module /initrd-2.6.32.26-174.2.xendom0.fc12.x86_64.img

The working F14 kernel entry is:
title Fedora (2.6.35.10-74.fc14.x86_64)
         root (hd1,0)
         kernel /vmlinuz-2.6.35.10-74.fc14.x86_64 ro 
root=/dev/mapper/RAID1-xenhost2 rd_LVM_LV=RAID1/xenhost2 
rd_MD_UUID=36de56a8:f0b5a953:26cc0f1b:25854d9c rd_NO_LUKS rd_NO_DM 
LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=us rhgb quiet
         initrd /initramfs-2.6.35.10-74.fc14.x86_64.img

For reference, here is the entry for my working CentOS install:
title CentOS
         root (hd1,0)
         kernel /xen.gz-3.4.3 cpufreq=xen dom0_mem=512M loglvl=all 
guest_loglvl=all dom0_max_vcpus=4 dom0_vcpus_pin
         module /vmlinuz-2.6.18-194.32.1.el5xen ro 
root=/dev/mapper/RAID1-xenhost
         module /initrd-2.6.18-194.32.1.el5xen.img