PowerVM Nova Driver
The IBM PowerVM hypervisor provides virtualization on POWER hardware. PowerVM admins can see benefits in their environments by making use of OpenStack. This driver (along with a Neutron ML2 compatible agent and Ceilometer agent) provides the capability for operators of PowerVM to use OpenStack natively.
As ecosystems continue to evolve around the POWER platform, a single OpenStack driver does not meet all of the needs for the various hypervisors. The standard libvirt driver provides support for KVM on POWER systems. This nova driver provides PowerVM support to OpenStack environment.
This driver meets the following:
- Built within the community
- Fits the OpenStack model
- Utilizes automated functional and unit tests
- Enables use of PowerVM systems through the OpenStack APIs
- Allows attachment of volumes from Cinder over supported protocols
This driver makes the following use cases available for PowerVM:
- As a deployer, all of the standard lifecycle operations (start, stop, reboot, migrate, destroy, etc.) should be supported on a PowerVM based instance.
- As a deployer, I should be able to capture an instance to an image.
- VNC console to instances deployed.
Overview of Architecture
The driver enables the following:
- Provide deployments that work with the OpenStack model.
- Driver is implemented using a new version of the PowerVM REST API.
- Ephemeral disks are supported either with Virtual I/O Server (VIOS) hosted local disks or via Shared Storage Pools (a PowerVM cluster file system).
- Volume support is provided via Cinder through supported protocols for the Hypervisor (virtual SCSI and N-Port ID Virtualization).
- Live migration support is available when using Shared Storage Pools or boot from volume.
- Network integration is supported via the ML2 compatible Neutron Agent. This is the openstack/networking-powervm project.
- Automated Functional Testing is provided to validate changes from the broader OpenStack community against the PowerVM driver.
- Thorough unit, syntax, and style testing is provided and enforced for the driver.
The intention is that this driver follows the OpenStack Nova model and will be a candidate for promotion (via a subsequent blueprint) into the nova core project.
Data Model Impact
No data model impacts are anticipated as part of this work.
REST API Impact
The intent of this work item is to enable PowerVM to fit within the broader OpenStack ecosystem, without requiring changes to the REST API.
As such, no REST API impacts are anticipated.
No new security impacts are anticipated.
No new notifications are anticipated.
Other End User Impact
The administrator will notice new logging messages in the nova compute logs.
It is a goal of the driver to deploy systems with similar speed and agility as the libvirt driver within OpenStack.
Most operations are comparable in speed. Deployment, attach/detach volumes, lifecycle, etc... are quick.
The driver is written to support concurrent operations. It has been tested performing 10 concurrent deploys to a given compute node.
Due to the nature of the project, performance impacts are limited to the Compute Driver. The API processes for instance are not impacted.
Other Deployer Impact
The cloud administrator will need to refer to documentation on how to configure OpenStack for use with a PowerVM hypervisor.
A 'powervm' configuration group is used to contain all the PowerVM specific configuration settings. Existing configuration file attributes will be reused as much as possible (e.g. vif_plugging_timeout). This reduces the number of PowerVM specific items that will be needed.
It is the goal of the project to only require minimal additional attributes. The deployer may specify additional attributes to fit their configuration.
There is no impact to customers upgrading their cloud stack as this is a genesis driver and does not have database impacts.
The code for this driver is currently contained within a powervm project. The driver is within the /nova_powervm/virt/powervm/ package and extends the nova.virt.driver.ComputeDriver class.
The code interacts with PowerVM through the pypowervm library. This python binding is a wrapper to the PowerVM REST API. All hypervisor operations will interact with the PowerVM REST API via this binding. The driver will be maintained to support future revisions of the PowerVM REST API as needed.
For ephemeral disk support, either a Virtual I/O Server hosted local disk or a Shared Storage Pool (a PowerVM clustered file system) is supported. For volume attachments, the driver supports Cinder based attachments via protocols supported by the hypervisor (e.g. Fibre Channel).
For networking, the networking-powervm project provides a Neutron ML2 Agent. The agent provides the necessary configuration on the Virtual I/O Server for networking. The PowerVM Nova driver code creates the VIF for the client VM, but the Neutron agent creates the VIF for VLANs.
Automated functional testing is provided through a third party continuous integration system. It monitors for incoming Nova change sets, runs a set of functional tests (lifecycle operations) against the incoming change, and provides a non-gating vote (+1 or -1).
Developers should not be impacted by these changes unless they wish to try the driver.
The intent of this project is to bring another driver to OpenStack that aligns with the ideals and vision of the community. The eventual impact is ideally to promote this to core Nova.
No alternatives appear viable to bring PowerVM support into the OpenStack community.
- Primary assignee:
- Other contributors:
thorst ijuwang efried
- Utilizes the PowerVM REST API specification for management. Will utilize future versions of this specification as it becomes available: http://ibm.co/1lThV9R
- Builds on top of the pypowervm library. This is a prerequisite to utilizing the driver.
Since the tempest tests should be implementation agnostic, the existing tempest tests should be able to run against the PowerVM driver without issue.
Thorough unit tests exist within the project to validate specific functions within this implementation.
A third party functional test environment will be created. It monitors for incoming nova change sets. Once it detects a new change set, it will execute the existing lifecycle API tests. A non-gating vote (+1 or -1) will be provided with information provided (logs) based on the result.
Existing APIs should be valid. All testing is planned within the functional testing system and via unit tests.
See the dev-ref for documentation on how to configure, contribute, use, etc. this driver implementation.
The existing Nova developer documentation should typically suffice. However, until merge into Nova, we will maintain a subset of dev-ref documentation.
- PowerVM REST API Specification (may require newer versions as they become available): http://ibm.co/1lThV9R
- PowerVM Virtualization Introduction and Configuration: http://www.redbooks.ibm.com/abstracts/sg247940.html
- PowerVM Best Practices: http://www.redbooks.ibm.com/abstracts/sg248062.html