Hi there,

The libvirt API (virsh) allows to set soft limits for CPU time (shares), disk IO (weight) and memory. tc (traffic control) in linux enables to prioritise network bandwidth of VMs.

Do there already exist methods to reallocate resources on the OpenStack layer at VM runtime?

I know about the flavour extra_specs, which are bound to the flavor (and reboot is required). Is the same thing already possible for instances? Is it even desirable to expose such libvirt functionality in the nova API?

I am asking because I've written a simple priority based nova extension to reallocate resources (memory, CPU time, disk IO and net bandwidth).

Thanks!