第13章 Configuring virtual GPUs for instances

To support GPU-based rendering on your instances, you can define and manage virtual GPU (vGPU) resources according to your available physical GPU devices and your hypervisor type. You can use this configuration to divide the rendering workloads between all your physical GPU devices more effectively, and to have more control over scheduling your vGPU-enabled instances.

To enable vGPU in the Compute (nova) service, create flavors that your cloud users can use to create Red Hat Enterprise Linux (RHEL) instances with vGPU devices. Each instance can then support GPU workloads with virtual GPU devices that correspond to the physical GPU devices.

The Compute service tracks the number of vGPU devices that are available for each GPU profile you define on each host. The Compute service schedules instances to these hosts based on the flavor, attaches the devices, and monitors usage on an ongoing basis. When an instance is deleted, the Compute service adds the vGPU devices back to the available pool.

13.1. Supported configurations and limitations

Supported GPU cards

For a list of supported NVIDIA GPU cards, see Virtual GPU Software Supported Products on the NVIDIA website.

Limitations when using vGPU devices

  • You can enable only one vGPU type on each Compute node.
  • Each instance can use only one vGPU resource.
  • Live migration of vGPU between hosts is not supported.
  • If you need to reboot the Compute node that hosts the vGPU instances, the vGPUs are not automatically reassigned to the recreated instances. You must either cold migrate the instances before you reboot the Compute node, or manually allocate each vGPU to the correct instance after reboot. To manually allocate each vGPU, you must retrieve the mdev UUID from the instance XML for each vGPU instance that runs on the Compute node before you reboot. You can use the following command to discover the mdev UUID for each instance:

    # virsh dumpxml <instance_name> | grep mdev

    Replace <instance_name> with the libvirt instance name, OS-EXT-SRV-ATTR:instance_name, returned in a /servers request to the Compute API.

  • Suspend operations on a vGPU-enabled instance is not supported due to a libvirt limitation. Instead, you can snapshot or shelve the instance.
  • By default, vGPU types on Compute hosts are not exposed to API users. To grant access, add the hosts to a host aggregate. For more information, see Creating and managing host aggregates.
  • If you use NVIDIA accelerator hardware, you must comply with the NVIDIA licensing requirements. For example, NVIDIA vGPU GRID requires a licensing server. For more information about the NVIDIA licensing requirements, see NVIDIA License Server Release Notes on the NVIDIA website.