Open Stack

On Feb 5, 2011, at 4:00 AM, openstack-operators-request at lists.openstack.org wrote:
> I have tried to find answer myself but I have not found it.
> 
> I would like to build a cloud where several server are powered down and I
> will power them on only on peak hours.
> 
> I need that virtual machines migrate to new servers and the migrate back
> when I power down them.
> 
> Is it possible?

With the current OpenStack Bexar release, I don't think that is feasible.

Assuming that your power down algorithm was something like:
	1. find all hosts with < x runnning VMs (where x is threshold of VMs feasible to migrate)
	2. consolidate/migrate those VMs onto other hosts (chosen by load)
	3. alert the scheduler that these VM-less hosts are powering down
	4. power down the hosts

We would need the live migration feature (https://blueprints.launchpad.net/nova/+spec/cactus-migration-live) that is coming in Cactus (April timeframe) and probably some changes to the scheduler (or maybe not ?) and instance monitor.  

And, of course, we would need actually code the algorithm that I have above :)

/k