[CentOS-virt] i386 VM on x86_64 host in Xen

Tue Dec 11 17:27:03 UTC 2007
Karanbir Singh <mail-lists at karan.org>

Scott Dowdle wrote:
> Karanbir,
> ----- "Karanbir Singh" <mail-lists at karan.org> wrote:
>> apart from mass scale hosting solutions, I am yet to see a role where
>> openvz actually provided a better all around VM solution than Xen.
> Depends on your definition of better.  One that works (for example the discussion you are having now about problems running i386 guests on x86_64 hosts) might fall into that. :)

the fact that openvz kernel does not boot my machine, takes it 
completely out of the working category. Neither is it capable of running 
selinux, which is another show stopped.

Also, none of the HA tools work for me under openvz.

They have a long way to go.

> There are uses where Xen is much better suited and OpenVZ isn't even a viable option.

Sure, thats what my point was. But my point also went on to say that 
aprt from high density hosting, I am yet to find a role where openvz was 
a better fit. I am open to hearing about your use cases :D

>> Even  the management tools and the developer support behind Xen far out 
>> weights that on openvz.
> I'm not sure what you mean by that.  OpenVZ comes from Virtuozzo which has been out over 6 years now and has been deployed by thousands (if not tens of thousands) of deployments.

sure, but again, only in high desity hosting solutions. I am yet to see 
a openvz deployment outside that.

> So far as management tools go, I wondering what management tools you use for Xen.  The only one I've really tried was Virtual Machine Manager and prior to the most recent release in 5.1, it couldn't even START a virtual machine.  I've tested out XenSource's management solution and while it has a few more features that Virtual Machine Manager, there still isn't much there.

Depends on the client setup, lots of people seem to rely on the amazon 
xen tools these days, along with Enomalism stuff.

btw, whats wrong with virsh ? you seem to be happy using cli tools for 
openvz, why not try the same sort of stuff on Xen as well ? Besides, I 
have never really used GUI pointty/clickity tools on such machines ( I 
think you get the idea that I am not in the hosting business :D )

> Given the 20ish resource parameters provided by OpenVZ and the vzctl command where all of those resources can be dynamically changed... and looking at /proc/user_beancounters on the hn or guests is the most direct way to monitor them... those rudimentary cli tools seem more up to the task than the current crop of GUI tools I see for Xen.  Although perhaps I'm just ignorant of additional management programs that are out there... and I look forward to you informing me.

right, so your ideas on Xen are mostly based on the lack of awareness. 
You can quite easily control and tweak runtime resources with Xen, that 
was one of the main selling points for it in the first place.

>> And for those mass hosting solutions, a bit of security minded setups would remove the need 
>> to have this sort of a virtual userspace  virtualising anyway.
> I'm not really sure what you mean, please clarify.

Most people who do high density hosting can achieve similar results / 
density without really needing a userspace vm model. eg. I know that 
$LargestHostingISP in .de is presently looking at howto educate the 
users that they might actually get a better deal with almost all the 
same resource access using shared hosting rather than VPS's running 
UML/Virtuzzo/Xen etc. Lets see how that pans out. At the moment, the 
idea and selling point of VPS's is that its a buzzword.

Karanbir Singh : http://www.karan.org/  : 2522219 at icq