Re: [Xen-users] Debian Repository

[Pasi Kärkkäinen <pasik@xxxxxx>]

On Wed, Jan 13, 2010 at 07:24:16PM -0000, Ian Tobin wrote:
> Hi,
> 
> So im a little confused again :)
> 

Heh.

> So we have our  Dom0 which we need running a xenified kernel from xen.org 
> (2.6.18) or a modified one from fedora. 
>

Fedora doesn't really ship Xen dom0 capable kernels nowadays. 
Fedora is waiting for pv_ops dom0 patches to get into upstream/kernel.org 
Linux kernel before they start shipping Xen dom0 kernels again.

They don't want to maintain separate (xenified) patches for each kernel, 
it's a lot of hard/extra work.

But Novell does exactly that for SLES and OpenSUSE. They have forward-ported 
the 
xenlinux/xenified patches from 2.6.18 to newer kernels.

>I was under the impression that with pv_ops we no longer need the xenified 
>kernel or is this the future plan?
> 

Jeremy's git tree has pv_ops based kernel, that has Xen dom0 support included. 
These pv_ops dom0 patches are not yet included in upstream kernel.org kernels.

So if you want to run pv_ops dom0 kernel today, you need to get the kernel
from Jeremy's git tree. The vanilla/upstream/mainline kernel.org Linux doesn't 
have dom0 support yet.

> If so what is the purpose of having a pv_ops domU? Is it just so we don't 
> have to find a xenified kernel? 
>

Well for a Xen guest kernel you can use the exact same kernel.org kernel you
would use on baremetal without Xen, because pv_ops domU support is included 
upstream. 
I think that's practical. That's where we're heading also with dom0.

> It seems to me there isn't much point if we still need the xenified dom0 
> kernel.
> 

You can use either xenified dom0 kernel, or a pv_ops dom0 kernel.
The plan is to get pv_ops dom0 patches accepted into upstream Linux in the 
future. 

We aren't there yet. It takes time and a lot of effort to get big
features/patches like dom0 accepted into upstream Linux.

> Hope you understand.
> 

Hopefully it's more clear now.

-- Pasi

> Thanks
> 
> Ian
> 
> -----Original Message-----
> From: Pasi Kärkkäinen [mailto:pasik@xxxxxx] 
> Sent: 13 January 2010 17:58
> To: Ian Tobin
> Cc: xen-users@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [Xen-users] Debian Repository
> 
> On Wed, Jan 13, 2010 at 05:55:15PM +0000, Ian Tobin wrote:
> > Can you compie the kernel from kernel.org and also compile xen from xen.org 
> >  and it work under pv op?
> > 
> 
> kernel from kernel.org will work as a Xen PV guest (=domU) kernel only.
> 
> If you need to compile a kernel that works as Xen dom0 kernel, then you
> need another kernel tree or some patches, see here:
> http://wiki.xensource.com/xenwiki/XenDom0Kernels
> 
> -- Pasi
> 
> > Sent from my iPod
> > 
> > On 13 Jan 2010, at 11:46, Pasi Kärkkäinen <pasik@xxxxxx> wrote:
> > 
> > >On Wed, Jan 13, 2010 at 11:37:12AM -0000, Ian Tobin wrote:
> > >>Right im with you.
> > >>
> > >>I take it the XENpatches are better though because they are not so  
> > >>generic and have better performance
> > >>
> > >
> > >At the moment the original "Xenlinux" patches, or the various
> > >forward-ports of them (by Novel/OpenSUSE), might be faster than  
> > >pv_ops.
> > >
> > >Also pv_ops dom0 patches are still lacking some features.. but
> > >development is happening all the time, so that will get fixed in the
> > >near future.
> > >
> > >In the future pv_ops (domU and dom0) is meant to be the one and only  
> > >correct solution.
> > >
> > >-- Pasi
> > >
> > >>Ian
> > >>
> > >>-----Original Message-----
> > >>From: Pasi Kärkkäinen [mailto:pasik@xxxxxx]
> > >>Sent: 13 January 2010 11:34
> > >>To: Ian Tobin
> > >>Cc: xen-users@xxxxxxxxxxxxxxxxxxx
> > >>Subject: Re: [Xen-users] Debian Repository
> > >>
> > >>On Wed, Jan 13, 2010 at 11:30:24AM -0000, Ian Tobin wrote:
> > >>>Ok i think i understand all that :)
> > >>>
> > >>>So if  compiled the the latest kernel enabling the xen options i  
> > >>>can run a DomU on the pv_ops framework?
> > >>>
> > >>
> > >>Yes, the upstream Linux kernel can be used as Xen PV domU kernel.
> > >>
> > >>Distributions like Fedora 10, Fedora 11, Fedora 12 contain pv_ops  
> > >>based
> > >>Xen PV domU kernels out-of-the-box.
> > >>
> > >>pv_ops makes it possible to run the exact same kernel binary on both
> > >>baremetal (without Xen) and on Xen PV domU/guest!
> > >>
> > >>-- Pasi
> > >>
> > >>>Ian
> > >>>
> > >>>-----Original Message-----
> > >>>From: Pasi Kärkkäinen [mailto:pasik@xxxxxx]
> > >>>Sent: 13 January 2010 11:10
> > >>>To: Ian Tobin
> > >>>Cc: xen-users@xxxxxxxxxxxxxxxxxxx
> > >>>Subject: Re: [Xen-users] Debian Repository
> > >>>
> > >>>On Wed, Jan 13, 2010 at 10:56:04AM -0000, Ian Tobin wrote:
> > >>>>Sorry im a bit confused, why have they added DomU support but no  
> > >>>>Dom0 support?
> > >>>>
> > >>>
> > >>>It's a long story. The 'original' Xenlinux patches (around Linux  
> > >>>2.6.18 timeframe,
> > >>>including dom0 support) were submitted for inclusion in upstream  
> > >>>Linux,
> > >>>but the patches were considered too intrusive, ie. they modified too
> > >>>much non-Xen generic x86 code, so the patches were not accepted  
> > >>>into Linux.
> > >>>
> > >>>That's when Xensource, VMware etc started working on a general
> > >>>paravirtualization framework for Linux. This was called pv_ops  
> > >>>(paravirt_ops).
> > >>>It took a long time to get the generic pv_ops framework in shape  
> > >>>and merged in Linux,
> > >>>and then after that Xen pv_ops domU support was merged in mainline  
> > >>>Linux.
> > >>>
> > >>>See here for history/changelog: 
> > >>>http://wiki.xensource.com/xenwiki/XenParavirtOps
> > >>>
> > >>>Today upstream/mainline Linux contains Xen domU support using the  
> > >>>pv_ops framework.
> > >>>
> > >>>>I was under the impression that pv_ops replaces Dom0 and you can  
> > >>>>run domU on pv_ops?
> > >>>>
> > >>>
> > >>>Jeremy (from Citrix/Xensource) is working on adding dom0 support to
> > >>>Linux pv_ops, so that mainline Linux can function as a dom0 kernel.
> > >>>
> > >>>Currently pv_ops dom0 patches are in Jeremy's git tree, and not yet
> > >>>accepted into upstream Linux. Jeremy is working hard on this.
> > >>>
> > >>>See XenParavirtOps wiki page for status updates.
> > >>>
> > >>>>That saying do i need a Dom0 if using pv_ops ?
> > >>>>
> > >>>
> > >>>Uhm.. you always need dom0 to manage and run Xen.
> > >>>Dom0 kernel can be based on pv_ops, or the old 'xenlinux' patches.
> > >>>
> > >>>Hopefully that clears it up.
> > >>>
> > >>>-- Pasi
> > >>>
> > >>>>Ian
> > >>>>
> > >>>>-----Original Message-----
> > >>>>From: Pasi Kärkkäinen [mailto:pasik@xxxxxx]
> > >>>>Sent: 13 January 2010 09:59
> > >>>>To: Ian Tobin
> > >>>>Cc: xen-users@xxxxxxxxxxxxxxxxxxx
> > >>>>Subject: Re: [Xen-users] Debian Repository
> > >>>>
> > >>>>On Wed, Jan 13, 2010 at 09:30:52AM -0000, Ian Tobin wrote:
> > >>>>>Just another quick one, if i downloaded the latest kernel from 
> > >>>>>kernel.org and compiled it would this have support for the latest XEN 
> > >>>>>release?
> > >>>>>
> > >>>>
> > >>>>vanilla kernel from kernel.org has Xen domU (guest) support  
> > >>>>included,
> > >>>>using the Linux pv_ops framework.
> > >>>>
> > >>>>Dom0 support is not yet included in kernel.org kernels.
> > >>>>
> > >>>>List of various dom0 capable kernels and patches here:
> > >>>>http://wiki.xensource.com/xenwiki/XenDom0Kernels
> > >>>>
> > >>>>-- Pasi
> > >>>>
> > >>>>>
> > >>>>>
> > >>>>>-----Original Message-----
> > >>>>>From: Pasi Kärkkäinen [mailto:pasik@xxxxxx]
> > >>>>>Sent: 13 January 2010 09:23
> > >>>>>To: Ian Tobin
> > >>>>>Cc: xen-users@xxxxxxxxxxxxxxxxxxx
> > >>>>>Subject: Re: [Xen-users] Debian Repository
> > >>>>>
> > >>>>>On Wed, Jan 13, 2010 at 09:07:17AM -0000, Ian Tobin wrote:
> > >>>>>>If Debian is not going to be supported for much longer what  
> > >>>>>>would the next best OS be?
> > >>>>>>
> > >>>>>
> > >>>>>If you read the posts, they're actively working on fixing the  
> > >>>>>packages.
> > >>>>>
> > >>>>>-- Pasi
> > >>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>-----Original Message-----
> > >>>>>>From: Pasi Kärkkäinen [mailto:pasik@xxxxxx]
> > >>>>>>Sent: 12 January 2010 14:20
> > >>>>>>To: Ian Tobin
> > >>>>>>Cc: xen-users@xxxxxxxxxxxxxxxxxxx
> > >>>>>>Subject: Re: [Xen-users] Debian Repository
> > >>>>>>
> > >>>>>>On Tue, Jan 12, 2010 at 04:16:31PM +0200, Pasi Kärkkäinen 
> > >>>>>> wrote:
> > >>>>>>>On Tue, Jan 12, 2010 at 12:44:32PM -0000, Ian Tobin wrote:
> > >>>>>>>>  Hi,
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>>  Im trying to install Netware and Windows 2008 server but im  
> > >>>>>>>>having
> > >>>>>>>>  problems with it reading the ISO.  Im guessing this is  
> > >>>>>>>>because im running
> > >>>>>>>>  version 3.2.1 debian packages so i want to upgrade to  
> > >>>>>>>>unstable and use the
> > >>>>>>>>  3.4 deb packages.
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>>  My problem is that there isn't a kernel package so when  
> > >>>>>>>>booting you cant
> > >>>>>>>>  boot into xenified kernel mode.  If i try and use a kernel  
> > >>>>>>>>from the stable
> > >>>>>>>>  tree it messes things up.
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>>  How is everyone else running the 3.4 packages? Ive read  
> > >>>>>>>>about pv_ops but i
> > >>>>>>>>  don't know how to install or use it.
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>>  Any ideas?
> > >>>>>>>>
> > >>>>>>>
> > >>>>>>>I think the Debian Xen 3.4.2 debs are also missing qemu-dm  
> > >>>>>>>required
> > >>>>>>>for Xen HVM guests.
> > >>>>>>>
> > >>>>>>>Debian developers are working on adding qemu-dm back to the  
> > >>>>>>>packages
> > >>>>>>>(it was removed because the Debian Xen maintainer didn't want  
> > >>>>>>>to maintain
> > >>>>>>>it, he thought managing/patching Qemu was too much work for  
> > >>>>>>>him).
> > >>>>>>>
> > >>>>>>>There was discussion about this on xen-devel and on debian pkg- 
> > >>>>>>>xen
> > >>>>>>>mailinglists:
> > >>>>>>>
> > >>>>>>>http://lists.xensource.com/archives/html/xen-devel/2009-12/msg00716.html
> > >>>>>>>and
> > >>>>>>>http://blog.xen.org/index.php/2009/12/15/support-to-be-removed-from-debian-squeeze-call-for-volunteers/
> > >>>>>>>
> > >>>>>>>You could always compile your own Xen dom0 kernel, there are  
> > >>>>>>>many
> > >>>>>>>options for that:
> > >>>>>>>
> > >>>>>>>http://wiki.xensource.com/xenwiki/XenDom0Kernels
> > >>>>>>>
> > >>>>>>
> > >>>>>>At the moment Linux 2.6.31.9 with OpenSUSE 2.6.31-10 Xen  
> > >>>>>>patches might
> > >>>>>>be a good option for you as a dom0 kernel.
> > >>>>>>
> > >>>>>>-- Pasi
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>
> > >>>>>
> > >>>>
> > >>>>
> > >>>
> > >>>
> > >>
> > >>
> > >
> 
> 

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