I am new to openstack . I noticed that when instance in openstack is powered-off . It do not return CPU and memory resources back to the pool . Is this normal behaviour or am I missing anything.
I am using openstack version 5.7 .
For example: In project ABC, 10 CPUs are allocated and if create one instance with all 10 cpus and even when I power-off the instances . It will show all CPUs are utilised and unable to setup new instance.
It is normal behavior. If the CPU or Memory resources were released, there would be no guarantee that you could power the instance on again. (What if the resources had been allocated to other instances, and you couldn't shut them down?)
If you want to release an instance's resources (apart from its IP addresses) without totally destroying it, consider shelving it.