OpenNebula 4.4 Beta (4.3.80) Retina

Nov 7th, 2013. The OpenNebula team is pleased to announce a beta release of OpenNebula 4.4 codename Retina. As a project driven by user needs, this release includes important features that meet real demands from production environments, with a focus on optimization of storage, monitoring, cloud bursting, and public cloud interfaces.

OpenNebula Retina includes support for multiple system datastores, which enables a much more efficient usage of the storage resources for running Virtual Machines. This feature ships with different scheduling policies for storage load balancing, intended to instruct OpenNebula to spread the running Virtual Machines across different storage mediums to optimize their use. This translates in the ability to define more than one disk (or other backend) to hold running VMs in a particular cluster. Monitorization subsystem in OpenNebula underwent a major redesign as well, effectively switching from a pulling mechanism to a pushing model, with the implications in scalability improvements.

An important effort has been made in the hybrid cloud model (cloud bursting). Using the AWS API tools have been deprecated in favor of the new Ruby SDK released, which allows the support of new AWS mechanisms like for instance IAM. Also, now is possible to fully support hybrid VM templates. Moreover, the AWS public cloud interface implemented by OpenNebula has been revisited and extended to support new functionality, as well as improved so the instance types are offered to the end user from OpenNebula templates.

We are now set to basically bug-fixing and feature-freeze. Note that this is a beta release aimed at testers and developers to try the new features, and send a more than welcomed feedback for the final release.

As usual OpenNebula releases are named after a Nebula. The Retina Nebula (IC 4406) is a planetary nebula near the western border of the constellation Lupus, the Wolf. It has dust clouds and has the shape of a torus.

What's New in OpenNebula 4.4 Beta

In the following list you can check the highlights of OpenNebula 4.4 Retina organised by component (a detailed list of changes can be found here):

OpenNebula Core: End-user functionality

OpenNebula 4.4 brings multiple new features to manage virtual machines:

OpenNebula Core: Internals & Administration Interface

There has been also several improvements for administrators and new features to enhance the robustness and scalability of OpenNebula core:

OpenNebula Drivers

The back-end of OpenNebula has been also improved in several areas, as described below:

Storage Drivers

Monitorization Drivers

  • New monitorization model, changed from a pull model to a push model, thus increasing the scalability of an OpenNebula cloud. More information here

Virtualization Drivers

  • VMware drivers improvements, like maintaining cloned target image format, improved vCenter integration

Networking Drivers

  • Security improvements in Open vSwitch, block ARP cache poisoning.


  • Support for cloud init, now OpenNebula is able to contextualize guests using cloud init.
  • Improvements in contextualization, ability to add INIT_SCRIPTS. Check this guide to learn how to define contextualization in your VM templates.

EC2 Public Cloud Improvements

Multiple improvements in the EC2 Public API exposed by OpenNebula:

  • VM snapshotting and VM tagging. Read this for more info on the offered EC2 functionality.
  • Better use of ONE templates in EC2 API, check more details here.

Hybrid Cloud (Cloud Bursting) Improvements

The hybrid (cloud bursting) drivers have been improved in a variety of areas:

  • Allow mixed templates, ability to have templates defining VMs locally and in Amazon EC2. More info here.
  • Adoption of Ruby SDK, for a better interaction with AWS.
  • EBS optimized option, now it can be passed to an Amazon VM. More info on EC2 specific tempalte attributes.
  • Extended host share variables, to cope with big regions modelled in OpenNebula.


  • Improved Apache integration, to allow uploading big images. More info on Apache and Sunstone integration here.
  • Better memcache integration, for more details on Sunstone for large scale deployments check this.
  • Multiple minor bugfixes: adding multiple tags of the same name, VM template wizard context fixes and updating, update quotas, attach disks problems, time format inconsistencies, tons of new tooltips, fixed typos, etc

Migrating from OpenNebula 4.2

A detailed upgrade process can be found in the documentation. For a complete set of changes to migrate from a 4.4 installation please refer to the Compatibility Guide.

:!: After OpenNebula upgrade make use you run onehost sync to update monitoring probes.

Getting the Software & Documentation

OpenNebula is released under the Apache 2.0 open source license. The complete source tree and binary packages for OpenNebula can be downloaded here.

Packages are available for various distros: Ubuntu LTS and latest, CentOS, OpenSUSE and Debian.

Please report any bug or send feedback at the development portal or at the mailing list.

The documentation of OpenNebula 4.4 can be found here.

Supported Platform Components

Because OpenNebula is inherently portable to different operating systems and virtualization platforms, most Linux distributions and Hypervisors are supported. However, not all platform configurations and combinations exhibit a similar functionality, performance and stability. You can contact us if you need advise about the best platform configurations and environments for functionality and performance. Please read our Certification Policy for more information.


The OpenNebula project would like to thank the community members and users who have contributed to this software release by being active with the discussions, answering user questions, or providing patches for bugfixes, features and documentation.

About OpenNebula

More information about the project can be found at the project web page. You may be also interested in checking the OpenNebula Ecosystem that includes many interesting projects contributed by the community to enhance or add new features to OpenNebula.