Comment 19 for bug 1978489

I think that the challenge of how to update the cpu tuning for all existing running instances is solvable.

a) quota:cpu_* is an additional property for a flavor and as such can be updated (applying to new instances created).

b) Using the virsh tool, its possible to live set the scheduling tuning on a running instance - for example:

sudo virsh schedinfo instance-0008905c --config --live --set cpu_shares=2048

That obviously needs tailoring for the actual running environment/instances.

That does not however deal with the in-balance between instances created before and post update with no flavor extra-specs defined - the default value for cpu_shares of 1024 should be used for existing instances with no explicit cpu_share extra spec.