[Engine-devel] qemu machine type / datacenter machine version

[Dor Laor]

On 04/06/2012 06:00 AM, Itamar Heim wrote:
>>>
>>>
>>> check this and reply to it:
>>> http://lists.ovirt.org/pipermail/users/2012-March/001439.html
>>
>> Since the topic was brought up, I have a long going request that oVirt
>> will enable users to run multiple machine type versions on the same host
>> (using the same qemu binary but providing a different -M compatibility
>> level per VM).
>>
>> Is that on the roadmap?
>
> I assume once will start with cluster level enumeration/monitoring first
> which is the bug which i asked to open around this thread.
> then look at per vm level (I'm guessing best way to make this easy to
> manage at per-vm level would be to use 'cluster default' for most vm's)
> I understand choosing cpu model per vm may (mainly for -cpu best) also
> be desirable in some cases.

Cpu model is a VM property. Setting anything beyond the least common 
denominator of your set of hardware hosts, may restrict using some of 
the older hosts as expected.

btw: -cpu best is less flexible for non homogeneous set of hosts. Better 
use an explicit model for such environment. In theory the newest models 
should perform just as good as -best