Engwar

Understanding OpenNebula

OpenNebula is a platform providing the ability to manage a pool of virtual resources. You can create virtual machines and configure them as you would configure a physical machine connected your network. Difference between OpenNebula and Amazon EC2 (and other public cloud providers) is that Amazon EC2 is a public service. Amazon is having an infrastructure management tool like OpenNebula which they use to provide those virtual resources to people in a pay-as-you-go scheme. You can use OpenNebula to provide similar kind of service to users inside your network. If you want to be another cloud service provider like Amazon, you can easily adapt OpenNebula to do that too. You only have to write a frontend which restricts creation of virtual machines only after a payment is made (on a very high level ). OpenNebula has an XMLRPC interface through which you can interface with from another program written in a different programming language. Also, OpenNebula provide a driver which expose it’s functionality through the libvirt API.

What is libvirt? Libvirt is an effort to come up with an API for all virtualization platforms. Plus, it does have an implementation (libvirtd) which other management programs can talk to. For example virsh and virt-manager are couple of tools which can talk to underlying virtualization platforms such as Xen and KVM through libvirt.

Going a step further than libvirt, OpenNebula eases the creation of networks, adding cluster nodes and deploying virtual machines. Also, OpenNebula comes with a scheduler which will deploy a given virtual machine on the cluster. Scheduling policies can be configured and if more complex policies are needed those can be created through Haizea. Haizea is a scheduler which can be plugged into OpenNebula. OpenNebula stores all these information in an SQLite database that can be accessed from any other programming language if those information needs to be pulled out. A nice to have feature would be an API that gives all kinds of information stored in the SQLite database.