This document discusses Nova, OpenStack's compute service, and provides an overview of: 1) Different compute models Nova supports including physical servers, virtualized servers using technologies like ESX, Hyper-V, KVM, Xen server, and container-based virtualization using LXC and OpenVZ. 2) Nova uses a driver-based approach to support different hypervisor technologies with drivers for KVM, ESX, Hyper-V, and others. 3) An example multi-hypervisor OpenStack cloud is shown supporting images, controllers, services, and compute hosts running Hyper-V, KVM, and ESXi. 4) Key features like physical bare-metal provisioning are supported across different

2. Legend :

3. Nova – compute service

4. Compute Models
• Physical Server as Compute
– Blades / Rack mount servers
• Virtualized Server as Compute
– ESX
– Hyper V
– KVM
– Xen server
• Other compute models
– Container based virtualization (LXC, OpenVZ)
– Partitions (lpar / Vpar)

5. Nova – driver based approach
Message Bus (Queue)
Libvirt Driver ViSDK driver WMI Driver
KVM
ESX Host Hyper V Host
Host

6. Multi Hypervisor Cloud
Glance Images
Grizzly Controller Keystone Database
(qcow2, vhd, vmdk) (Devstack) (Mysql)
Asynchronous message queue
Hyper-V KVM
VM VM
Win-8 Win-8 RHEL Ubuntu Compute Compute
Compute -WMI Compute -WMI
Compute - libvirt Compute - libvirt VI SDK
ESXi 5.0 ESXi 5.0
VM VM VM VM VM
VM VM VM
1 2 1 2 2
1 2 1
VM VM
Switch Switch bridge bridge VSS VSS
ESXi

7. OpenStack - feature supported across Hypervisors

8. Physical Bare-metal provisioning

9. Q&A

10. •nova-computewith the bare-metal driver: The bare-metal driver itself consists of several
components:
•The power manager is responsible for operations such as setting boot devices, powering
up and down nodes, etc. It’s robust enough to support several management protocol
implementations (we developed two, based on IPMIoool and FreeIPMI to support a wider
range of hardware).
•The network manager interacts with the rack switch and is responsible for switching
nodes back and forth between the service and projects’ networks (the service network is
used to deploy the bare-metal instance via PXE/TFTP). Currently we have an
implementation for the Juniper switches. More details on that will be provided in another
post devoted to networking support.
•dnsmasq is a Netboot environment for instance provisioning.
•nova-baremetal-agent: This is the agent that is supposed to be run on bootstrap-linux
(see the next bullet) and executes various provisioning tasks spawned by the bare-metal driver.
•bootstrap-linux: A tiny Linux image to be booted over the network and perform basic
initialization. It is based on the Tiny Core Linux and contains a basic set of packages such as
Python to run nova-baremetal-agent (which is implemented in Python) and curl to be able to
download an image from Glance. Additionally, it contains an init script that downloads nova-
baremetal-agent using curl and executes it.
•nova-baremetal-service: A service that is responsible for orchestration of the provisioning
tasks (tasks are applied by nova-baremetal-agent directly to the bare-metal server it is
running on).

12. What is Cloud?
On-demand Measured service.
self-service.
Internet
Broad network
access.
Rapid elasticity.
Resource pooling.
Cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a
shared pool of configurable computing resourcesresources (hardware and software) that are
Cloud computing is the use of computing (e.g., networks, servers, storage, applications, and
services) that can be rapidly provisioned and released with minimal management effort or service
delivered as a service over a network ( Internet )
provider interaction. – NIST definition

13. LXC