Xen users - Aug 2009 - Difference between xenified and pv_ops kernel

Hi,

we have successfully tried to run both xenified and pv_ops 2.6.30
kernels for DomU.

How would you describe the main difference between those two approaches?

What is the main difference?
Are the possibilities the same?
What about speed?

Our needs for domu are pretty low - some CPU, some RAM, lvm HDD, 1-3
virtual NICs. That''s all.
Nothing like PCI/USB passtrough - just plain VPS linux machine.

Differences from our point of view:

1) pv_ops can be used even with latest 2.6.31-rcX kernels
2) xenified kernel currently with 2.6.30.2 only
3) in XM TOP idling VPS with xenified kernel is really not consuming
CPU(secs) while
    VPS with pv_ops kernel is always using like 1-3% of CPU even when
guest OS idle.


Thanks for your opinion


Br

Peter

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

On Mon, Aug 17, 2009 at 05:05:56PM +0200, Peter Braun
wrote:
> Hi,
> 
> we have successfully tried to run both xenified and pv_ops 2.6.30
> kernels for DomU.
> 
> How would you describe the main difference between those two approaches?
> 
> What is the main difference?
> Are the possibilities the same?
> What about speed?
> 
> Our needs for domu are pretty low - some CPU, some RAM, lvm HDD, 1-3
> virtual NICs. That''s all.
> Nothing like PCI/USB passtrough - just plain VPS linux machine.
> 
> Differences from our point of view:
> 
> 1) pv_ops can be used even with latest 2.6.31-rcX kernels
pv_ops Xen domU support has been there since Linux 2.6.24, and like you
said, it is included in the upstream/mainline Linux kernel, so it''s
always
there to use without extra patches.

Also with pv_ops the same kernel image can be used on baremetal (without
Xen), and also as Xen domU.
> 2) xenified kernel currently with 2.6.30.2 only
Yes it''s separate patching, and custom forward-porting, so pv_ops is
much
easier solution.
> 3) in XM TOP idling VPS with xenified kernel is really not consuming
> CPU(secs) while
>     VPS with pv_ops kernel is always using like 1-3% of CPU even when
> guest OS idle.
> 
> 
-- Pasi

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

On Mon, Aug 17, 2009 at 10:05 PM, Peter Braun<xenware@gmail.com>
wrote:
> Hi,
>
> we have successfully tried to run both xenified and pv_ops 2.6.30
> kernels for DomU.
>
> How would you describe the main difference between those two approaches?
See http://wiki.xensource.com/xenwiki/XenParavirtOps
IMHO the biggest user-visible difference is supported features, like
balloon expansion. When using xenfied kernel its possible to do assign
something like 512MB to domU on startup but allow it to dynamically
grow online to (say) 4GB later when neede.

-- 
Fajar

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users