[Users] How to define max number of running VMs on a host?

[lofyer]

On 2013/8/22 18:07, Itamar Heim wrote:
> On 08/22/2013 05:24 AM, lofyer wrote:
>> On 2013/8/22 17:17, Itamar Heim wrote:
>>> On 08/21/2013 01:19 AM, lof yer wrote:
>>>> I didn't see anything like this in engine-config.
>>>> Is it possible to do that without using host-hooks?
>>>>
>>>>
>>>> _______________________________________________
>>>> Users mailing list
>>>> Users at ovirt.org
>>>> http://lists.ovirt.org/mailman/listinfo/users
>>>>
>>>
>>> can you explain the use case a bit?
>> I have 4 graphic workstations with 3 graphic cards on each. I wanna
>> passthrough graphic cards to the VMs one by one, since one workstation
>> has only 3 cards,  I must limit the number of running VM on a host to 3.
>
> 1. I assume you use a hook for the graphic passthrough?
> you can just fail it if no more devices, and engine will try to 
> schedule on next host.
>
> 2. (ab)use the reserved RAM. if you allocate to each VM reserved RAM 
> so 3 VMs can fit a host but 4 can't, engine won't try to schedule more 
> than 3 on the same host as it would violate the reserved rAM
>
> 3. not a hook, but a filter. in 3.3 you can write a new filter to the 
> pluggable scheduler of "MaxNumberOfVms" and pass a property of 3 to it.
Thank you very much, I think the filter is very suitable for this senerio.