summary of mirantis openstack integrating with vsphere

Fuel 5.0 and later can deploy a Mirantis OpenStack environment that boots and manages virtual machines in VMware vSphere.VMware provides a vCenter driver for OpenStack that enables thenova-compute service to communicate withaVMware vCenter server that manages one or more ESXi host clusters. 

Please, note the following:

VMware provides a vCenter driver for OpenStack. This driver enables the Nova-compute service to communicate with a VMware vCenter server that manages one or more ESXi host clusters. The vCenter driver makes management convenient from both the OpenStack Dashboard (Horizon) and from vCenter, where advanced vSphere features can be accessed.

This enables Nova-compute to deploy workloads on vSphere and allows vSphere features such as vMotion workload migration, vSphere High Availability, and Dynamic Resource Scheduling (DRS). DRS is enabled by architecting the driver to aggregate ESXi hosts in each cluster to present one large hypervisor entity to the Nova scheduler. This enables OpenStack to schedule to the granularity of clusters, then call vSphere DRS to schedule the individual ESXi host within the cluster. The vCenter driver also interacts with the OpenStack Image Service (Glance) to copy VMDK (VMware virtual machine) images from the back-end image store to a database cache from which they can be quickly retrieved after they are loaded.

The vCenter driver requires the Nova Network topology, which means that OVS (Open vSwitch) does not work with vCenter.

The Nova-compute service runs on a Controller node, not on a separate Compute node. This means that, in the Multi-node Deployment mode, a user has a single Controller node with both compute and network services running.

Unlike other hypervisor drivers that require the Nova-compute service to be running on the same node as the hypervisor itself, the vCenter driver enables the Nova-compute service to manage ESXi hypervisors remotely. This means that you do not need a dedicated Compute node to use the vCenter hypervisor; instead, Fuel puts the Nova-compute service on a Controller node.

• In 5.x environments that use vCenter as the hypervisor, the nova-compute service runs only on a Controller node, not on a separate Compute node. This means that, in the Multi-node Deployment mode, a user has a single Controller node with both compute and network services running.If your vCenter manages multiple ESXi host clusters, Fuel 5.1 allows you to specify several or all clusters for a single OpenStack environment, so that one nova-compute service manages multiple ESX host clusters via single vCenter server(fuel5.1).
• In 6.0 Fuel release, the relation between a nova-compute service and an ESXi host cluster is changedfrom one-to-many to one-to-one (so-called 1-1 mapping). In other words,to manage multiple ESXi host clusters, you now need to run multiple nova-compute services.
• In Fuel6.1,each OpenStack environment can support more than one vCenter cluster.Beginning with Fuel 6.1, vCenter cannot be integrated with NSX: NSX support is now deprecated. Due to Pluggable Architecture, it might be turned into a plugin in the future Fuel releases.
  
• In Fuel 6.1, Ceilometer compute service is available for each vSphere cluster. That means,every agent polls resources about instances from those that only relate to their vSphere cluster. Every agent uses its own configuration file with authentication parameters for its specific vSphere cluster. See Related projects for vCenter for more details.

Nova-compute and vSphere clusters mapping

In earlier Fuel releases, 1-N mapping between nova-compute service and vSphere cluster (cluster that is formed from ESXi hosts by vCenter server) was used. In most cases, a single nova-compute service instance uses many vSphere clusters, managed by a single vCenter. Beginning with 6.1 Fuel release, this behaviour was changed to 1-1 mapping, so that a single nova-compute service instance now interacts with a single vSphere cluster.

Dual hypervisor support

Beginning with Fuel 6.1, you can deploy an environment with two hypervisors: vCenter, KVM/QEMU using availability zones.

The vCenter driver makes management convenient from both the OpenStack Dashboard (Horizon)and from vCenter, where advanced vSphere features can be accessed.This enables Nova-compute to deploy workloads on vSphere and allows vSphere features such as vMotion workload migration, vSphere High Availability, and Dynamic Resource Scheduling (DRS). DRS is enabled by architecting the driver toaggregate ESXi hosts in each cluster to present one large hypervisor entity to the Nova scheduler. This enables OpenStack to schedule to the granularity of clusters, then call vSphere DRS to schedule the individual ESXi host within the cluster. The vCenter driver also interacts with the OpenStack Image Service (Glance) to copy VMDK (VMware virtual machine) images from the back-end image store to a database cache from which they can be quickly retrieved after they are loaded.

Unlike other hypervisor drivers that require the Nova-compute service to be running on the same node as the hypervisor itself, the vCenter driver enables the Nova-compute service to manage ESXi hypervisors remotely. This means that you do not need a dedicated Compute node to use the vCenter hypervisor; instead, Fuel puts the Nova-compute service on a Controller node.

Limitations

• Only vCenter versions 5.1 and later are supported
• Security groups are not supported.
• The only supported backend for Cinder is VMDK.
• Volumes that are created by Cinder appear as SCSI disks. To be able to read/write that disk, be sure that the operating system inside the instance supports SCSI disks. The CirrOS image that is shipped with Fuel supports only IDE disks, so even if the volume is attached to it, CirrOS is not able to use it.
• The Ceph backend for Glance, Cinder and RadosGW object storage is not supported.
• Murano is not supported. It requires Neutron and vCenter utilizes nova-network.