Hi,

in principle VirtualizationType can be selected differently for the same image, because is the flavor that enables the access to the accelerator.

For example, VirtualizationType for GPUs depends on how is configured the cloud framework and strongly depends on the hypervisor, e.g. KVM only support PCI-passthrough virtualization (it implies max 1 VM attached to a physical accelerator) while WMware can also support NVIDIA GRID vGPU based virtualization (it allows more VMs can share the same physical accelerator).

In OpenStack configured with PCI-passtrough, you need to define a flavor with a flavor-key like e.g. "pci_passthrough:alias"="GPU:2" in order to allow any image to have access to two GPUs whose hardware info is in a configuration line like "pci_alias = {"vendor_id":"xxxx","product_id":"xxxx", "name":"GPU"}" in nova.conf, so i would consider as a right place for the VirtualizationType attribute the CloudComputingVirtualAccelerator entity, that is associated to the CloudComputingInstanceType class (representing the flavor).

Marco

On 21/09/2017 12:41, stephen.burke@stfc.ac.uk wrote:

glue-wg [mailto:glue-wg-bounces@ogf.org] On Behalf Of Alessandro Paolini said:

Initially I was thinking that CloudComputingVirtualAccelerator class was better, but know it seems to me
that both the classes are suitable for containing this attribute, it can be either into one or another: do
you think we can add it to both the classes?

I don't know enough about how it works ... normally something which is part of the description of the WN environment would be in Resource, which seems to be the VirtualAcclerator here. The question I'd ask is whether the VirtualizationType is bound to the VM image or whether it's something which could be selected differently for the same image according to choices made when the job is submitted.

Stephen

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Marco Verlato Ph.D
Istituto Nazionale di Fisica Nucleare - Sez. di Padova
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Office: Room 110, Via Belzoni 7
Phone:+390499677361, Fax:+390498275952, Email:verlato(at)pd.infn.it
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