VMware: dual hypervisor support


Add a functionality to Fuel that allows end user deploy dual hypervisor OpenStack cloud.

Term “dual hypervisor cloud” in this document has the following meaning: OpenStack cloud that can provision virtual machines on two hypervisors simultaneously. This specification describes two possible dual hypervisor cloud setups:

  • KVM and vCenter
  • QEMU and vCenter

Problem description

As of Fuel 6.0, it allows end user to add compute nodes only with hypervisor type that was selected during environment creation. Fuel does not allow increase compute resource pool by extending it with resources of another hypervisor type.

Right now user selects hypervisor type in “Create a new OpenStack environment” wizard. It is not possible to use KVM/QEMU compute nodes simultaneously with vCenter and vice versa, since Fuel web UI restricts it.

Proposed change

Right now Fuel deploys nova-compute services with vCenter compute driver on OpenStack controllers, in this specification we do not propose to change this behaviour. Restriction in Fuel web UI must be eliminated and cluster creation wizard step where user selects hypervisor must be reworked. Instead of three radio buttons that represent possible hypervisors (KVM, QEMU, vCenter), vCenter must present on this page as checkbox. If user selected this checkbox, VMware settings tab [0] will appear on the cluster page after cluster creation wizard is finished. It is up to user to add vCenter to this environment. Compute nodes become optional for this cluster, user may configure only vCenter related settings and deploy cluster with controller nodes only.

After implementing this specification, the following use case will be available from end user perspective:

  1. Create new HA OpenStack environment with nova-network as network provider
  2. User adds 3 controllers and a bunch of KVM computes and cinder nodes
  3. User fills vCenter related settings on the VMware tab [0]
  4. In OpenStack dashboard user sees that there are several availability zones (zones that he created on VMware settings tab and “nova” if cluster contains any KVM/QEMU compute nodes)
  5. Deploy the cluster
  6. Now user is able to run VMs on KVM or vSphere

In order to support OpenStack Block storage for vCenter, we also have to introduce new role for Cinder service with VMDK backend [1].

This specification does not cover a vCenter removal procedure.

Implementation of this change must not affect end user opportunity to deploy KVM only or vCenter only cloud.



Data model impact


REST API impact


Upgrade impact


Security impact


Notifications impact


Other end user impact

Fuel web UI cluster creation wizard will be modified.

Performance Impact


Other deployer impact

Special attention must be payed to the fact that for vCenter Fuel deploys nova-network service in non-multi host mode (there is a single nova-network service for whole OpenStack cluster), while in KVM/QEMU case nova-network is deployed on compute nodes (multi host mode).

Developer impact

  • OSTF tests must be reworked to support proposed change. Separate OSTF manager must be implemented.
  • All vCenter related system tests must be adjusted (accept availability zones, etc).
  • Ceilometer support for vCenter is affected by this change.



Primary assignee:
izinovik (Igor Zinovik) srogov (Stepan Rogov)
Core reviewers:
vkuklin (Vladimir Kuklin)
Other contributors:
gcon.monolake (Andrey Danin) okosse (Oleksandr Kosse)

Work Items

  • Modify cluster creation wizard that way that it allows select a combination of hypervisors KVM with vCenter or QEMU with vCenter. Change vCenter radio button to checkbox.
  • Remove restriction that forbids to add compute nodes with vCenter settings.
  • Adapt Fuel library puppet manifests to new structure of astute.yaml that will be formed by Nailgun backend, due to VMware settings tab [0].
  • Names of Cirros images that get loaded into Glance must be modified, so that user will able to distinguish easily, which image can be run on KVM/QEMU and which on vCenter. Currently images are named as TestVM.
  • Implement post deploy hook in astute for availability zone creation and assignment vCenter nova-compute services to corresponding availability zones.
  • Assign KVM/QEMU compute nodes and vCenter to availability zones.
  • Implement vCenter OSTF manager.
  • Implement system tests for dual hypervisor cluster.


Existing tests that create KVM only or vCenter only must not be affected.

Following testing scenarios must be implemented:

  • Create cloud with KVM compute nodes, fill settings for vCenter, deploy cluster, run OSTF checks. Expected result: the cloud is successfully deployed, two images present in Glance, one for KVM and another one for vCenter. User can run virtual machines on each hypervisor.
  • Deploy cluster with two types of storage nodes: cinder with LVM backend and cinder with VMDK backend. Expected result: virtual machine can attach storage of appropriate type.
  • Virtual machines running on different hypervisors are able to communicate with each other.

Documentation Impact

Most part of documentation related to vCenter must be adjusted to reflect changes described in this specification (Planning Guide, User Guide). New section must be added: instructions on planning and deployment of dual hypervisor environment (limitations, reference architecture).