Comment 3 for bug 1829349

For #1
Yes

For #2
In my ENV for some reason placement is not enabled.
So scheduler can only depend on information RT provided to make decision. And because NUMA conflict RT failed to report usage.

As a result scheduler will always think this host has enough resource to boot new VMs.
At this situation
resize or create will claim fail, when there is really not enough resource available or there is numa conflict. But still will boot more VMs than expected.

but live migration do not claim, it will always success, so in my case, this is the problem.

If placement is enabled, seems
"The result is RT failed to update usage to Scheduler. And Eventually cause scheduler always think this host has enough resource to boot new VMs. So the result is disaster."
can be prevented by placement.

So to summary,
The problem is when there is numa conflict, RT will not able to update usage to scheduler, which will cause hypervisor resource usage info not correct.