Copy Offload for instance creation


We configured Copy Offload and see the tool is working between Cinder and Glance. (Ontap - Edge cDOT 8.3 - NFS ; OpenStack Kilo Release).

The question is regarding creation of an instance by using an image (Glance) or volume (Cinder). Seems The VM (instance) is ready only after coping data, probably between cinder and compute nodes.

In the environemnt there are 2 compute servers, 1 cinder server and 1 controller server with nova services.
It seems that because cinder mounts are on one server, and compute services on another server, the communication between them is done by copying the data between the servers.
Any recommendation how to resolve it ? Should the compute servers be mounted to the cinder volumes as well ?




Re: Copy Offload for instance creation

In my experience, the host running the Nova compute services *should* mount the remote volume hosted on the NetApp system on its own whenever an instance is tasked to be started by the scheduler on that pertinent host.  This provides the host the necessary VM files to boot from volume via calls to libvirt.


You can verify this with the "nova show <UUID>" command on the VM you're interested in after sourcing the pertinent admin rc file.  See which host the instance is running on via the command output and make sure it has the remote FlexVol mounted via the "mount" command.