[Yoga][Magnum] change boot disk storage for COE VMs

Hi,

When creating Magnum clusters, two disks are created for each VM sda and sdb, the sda is the boot disk and the sdb is for docker images. By default the sda is created (at least in my deployment) in nova vms pool, as ephemeral disks, the second disk sdb is created in cinder volume.

Is it possible to move the sda from nova vms to cinder volume?

I tried with default_boot_volume_type, but it didn't work. default_boot_volume_type = MyCinderPool

Regards.