As the figure shows, the OpenStack Compute Scheduler sees three hypervisors that each correspond to a cluster in vCenter. Nova-compute contains the VMware driver. You can run with multiple nova-compute services. While Compute schedules at the granularity of a cluster, the VMware driver inside nova-compute interacts with the vCenter APIs to select an appropriate ESX host within the cluster. Internally, vCenter uses DRS for placement.
The VMware vCenter driver also interacts with the OpenStack Image Service to copy VMDK images from the Image Service back end store. The dotted line in the figure represents VMDK images being copied from the OpenStack Image Service to the vSphere data store. VMDK images are cached in the data store so the copy operation is only required the first time that the VMDK image is used.
After OpenStack boots a VM into a vSphere cluster, the VM becomes visible in vCenter and can access vSphere advanced features. At the same time, the VM is visible in the OpenStack dashboard and you can manage it as you would any other OpenStack VM. You can perform advanced vSphere operations in vCenter while you configure OpenStack resources such as VMs through the OpenStack dashboard.
The figure does not show how networking fits into the architecture. Both nova-network and the OpenStack Networking Service are supported. For details, see the section called “Networking with VMware vSphere”.
Configuration overview
To get started with the VMware vCenter driver, complete the following high-level steps:
Configure vCenter. See the section called “Prerequisites and limitations”.
Configure the VMware vCenter driver in the nova.conf file. See the section called “VMware vCenter driver”.
Load desired VMDK images into the OpenStack Image Service. See the section called “Images with VMware vSphere”.
Configure networking with either nova-network or the OpenStack Networking Service. See the section called “Networking with VMware vSphere”.
Links:
http://www.vmware.com/files/pdf/techp...
http://docs.openstack.org/trunk/confi...