Technology Preview Overview is pleased to announce a Technology Preview of OpenNebula (ONE), a virtual infrastructure engine that enables the dynamic deployment and re-allocation of virtual machines on a pool of physical resources. ONE (OpenNebula) extends the benefits of Xen virtualization technology from a single physical resource to a pool of resources, decoupling the server not only from the physical infrastructure but also from the physical location.

Feature Summary

The OpenNebula Virtual Infrastructure Engine differentiates from existing VM managers in its highly modular and open architecture designed to meet the requirements of cluster administrators.

  • Efficient Resource Management. The scheduling module provides a generic framework to build any scheduling policy. The default scheduling policy determines the best host to start a VM according to requirement and rank expressions consisting on infrastructure parameters.
  • Centralized Management. A single access point to manage a pool of VMs and physical resources.
  • 3rd Party Software Integration. The OpenNebula Engine provides a command line interface for monitoring and controlling VMs and physical resources quite similar to that provided by well-known cluster management services. Such interface allows its integration with third-party tools, such as LRMs (Local Resource Managers), service adapters, VM image managers…; providing a complete solution for the deployment of flexible and efficient virtual infrastructures.
  • Open and Flexible Architecture. The access to the hypervisors is performed through customizable programs. So the administrator can taylor the behavior of OpenNebula by adding new infrastructure metrics and parameters or even supporting new Hypervisors.
  • Ease of Installation and Administration. OpenNebula is installed on a cluster front-end without requiring the installation of new services in the remote resources, apart from the Xen Hypervisor.
  • Open Source Software. OpenNebula is open source software released under Apache license v2.0 and support is provided through a mailing lists.
  • OpenNebula is an Active Project. We are working to extend its functionality. Please check the Roadmap Section.

Technology Dependencies


The ONE Server machine needs to have installed the following software:

  • ruby >= 1.8.5
  • sqlite3 >= 3.5.2
  • sqlite3-dev >= 3.5.6-3
  • sqlite3-ruby
  • libxmlrpc-c >= 1.06
  • scons >= 0.97

Most of this software is already packaged in linux distributions. Here are the packages needed in a debian lenny.

  • ruby: ruby
  • sqlite3: libsqlite3-0, sqlite3
  • sqlite3-dev : libsqlite3-dev
  • sqlite3-ruby: libsqlite3-ruby
  • libxmlrpc-c: libxmlrpc-c3-dev, libxmlrpc-c3
  • scons: scons


Provisioning hosts (here Host 1 and Host 2) need to have installed:

  • ruby >= 1.8.5
  • sudo >= 1.6.9
  • xen >= 3.1

Supported Platforms

  • Linux : Tested with the Debian distribution.
  • Mac OS X 10

Known Problems

  • The ONE database file (that lives in $ONE_LOCATION/var/one.db) must be placed on a local folder on the ONE server. The sqlite driver to access the DB doesn't handle correctly NFS locks. But ONE needs it's var folder to be exported via NFS, for checkpointing. Therefore, the recommended setup is to place the ONE installation in the same host that exports NFS folders, installing it in one of such exported folders.
    • Whenever the possibility to install ONE in the NFS server is unfeasible, there is a solution involving a soft link that points from ONE's var directory to a local empty file called one.db that will be used as the ONE database. A sample of a bash command that will perform this operation is:
$> mkdir /var/spool/nebula  
$> touch /var/spool/nebula/one.db  
$> ln -s /var/spool/nebula/one.db $ONE_LOCATION/var/one.db

After this make sure this file is readable and writable by <oneadmin> user.