OpenNebula Flame (4.2)

July 26th, 2013. The OpenNebula team is pleased to welcome the summer with the immediate availability of the final version of OpenNebula 4.2, codename Flame. Our goal with this release is to reduce your waiting time to test some exciting new features that are currently ready!

OpenNebula Flame includes a more polished Sunstone interface, after its redesign in 4.0; with important usability enhancements. Datastore capacity is now monitored and used to limit the amount of storage size used by images. This is a first step to also control the runtime storage used by the VMs. The VMware backend has been completely redesigned with a more comprehensive storage scheme, more functionality and less dependencies. Also we have upgraded the Xen backend to support the new interfaces introduced in Xen 4.0. And last but no least, OneFlow, the multi-tier application (a.k.a. service) manager, it is included and fully integrated in the distribution. It includes also important new features related to service management and elasticity/auto-scaling.

This is a stable release and so a recommended update that incorporates several bug fixes since 4.2 Beta. We've done our best to keep compatibility with OpenNebula 4.0, so any application developed for previous versions should work without effort. In any case, be sure to check the compatibility and upgrade guides.

As usual OpenNebula releases are named after a Nebula. The Flame Nebula (catalogued as NGC 2024 and Sh2-277) is an emission nebula in the constellation Orion. It is located about 900 to 1,500 light-years away from Earth.

What's New in OpenNebula 4.2

In the following list you can check the highlights of OpenNebula 4.2 Flame organised by component (a detailed list of changes can be found here):

OpenNebula Core

  • Datastore Monitoring, the capacity of the datastores is now monitored by the drivers. This will help users and admins to quickly identify the resource usage of the cloud. Admins can also set security threshold in capacity usage.
  • New Hooks, you can now program hooks on any transition. Also the information of the previous state can be passed as a hook argument to customized the action depending on the original VM state. Read more about this here.

OpenNebula Drivers

  • VMware, the whole set of VMware drivers, storage, networking and virtualization has been greatly improved. The storage system has been simplified and made more efficient, see more here. This change was made to favour the most demanded and useful combination, in order to focus efforts and stabilize it. The networking drivers have been also streamlined. Monitoring of ESXi hosts is now complete and the functionality of the virtualization drivers is now levelled with KVM and Xen. In the process the runtime dependencies of VMware has been reduced by accessing the native VMware VI API.
  • Xen, support for the Xen4 interfaces through the xl command. Xen3 is totally supported with its own set of drivers. More on this in the Xen guide.

OpenNebula Gate (New Component!)

OpenNebula Gate (onegate) is the VM gate to OpenNebula.

  • With a security token the VMs can call back home and report guest and/or application status in a simple way, that can be easily queried through OpenNebula interfaces (Sunstone, CLI or API).
  • OpenNebula Gate metrics can be also used in conjuntion with OneFlow to develop advanced auto-scaling policies. More information about OpenNebula Gate here.


Sunstone has been polished since its redesign in 4.0:

  • Improved VNC, you can now detach VNC sessions from the Sunstone tab. This let you use the whole window area, prevents synchronisation problems with mouse pointers, and… yes! ESC key now works!
  • VM definition update, the template dialog is also used to update your VM definitions without the need to go to the text based view.
  • Performance improvements, internal improvements in the information management and resource access.
  • Self-service view, we have a created a “cloudy” provisioning scheme for users, see more on this here.

OpenNebula Flow (New Component!)

This release is the first one to include the OpenNebula OneFlow component (former AppFlow component available in OpenNebulaApps). OneFlow allows users and administrators to define, execute and manage multi-tiered applications, or services composed of interconnected Virtual Machines with deployment dependencies between them. This version also comes with handy new features:

  • Auto-scaling policies: A service is composed by roles, each one corresponding to one VM template and each one with certain cardinality, ie, the number of instances of the same VM template. A role's cardinality can be adjusted manually, based on metrics, or based on a schedule. Read more here
  • Service management has been greatly improved, with the ability to recover from fault situations, the ability to apply operations to all the VMs belonging to certain role, the ability to define a cooldown period after a scaling operations, … and many other useful features
  • Apply scheduling actions to the VMs that conforms a role.
  • Updated sunstone interface

Migrating from OpenNebula 4.0

There have been minor changes in the OpenNebula DB schema to support the new datastore monitor subsystem. These changes are automatically managed by the migration process, but if you have developed any customisation you may need to update it.

A detailed upgrade process can be found in the documentation. For a complete set of changes to migrate from a 4.0 installation please refer to the Compatibility Guide.

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 4.2 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.

Certified Platform Components

This is the list of the individual platform components that have been through the complete OpenNebula Quality Assurance and Certification Process.

Certified Platform Component Version
RedHat Enterprise Linux 6.4
Ubuntu Server 12.04 (LTS) & 13.04 (Latest)
SUSE Linux Enterprise 12.3
CentOS 6.4
openSUSE 12.3
Debian 7.1
VMware ESX 5.0 & ESX 5.1
Xen 3.2 & 4.2
KVM Supported version that is included in the kernel for the Linux distribution
Xen Server, Xen Cloud Platform, and Hyper-V  Please contact us if you are interested in these hypervisors


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.

The new features for service elasticity (oneFlow) introduced in OpenNebula 4.2 were funded by BlackBerry in the context of the Fund a Feature Program.

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.