OpenNebula

OpenNebula

As mention in one of the blog posts,  I decided to use OpenNebula because of the CPU limitations on the compute hosts.  The Phenom II chips in the compute hosts will work fine with KVM, however, Ovirt didn't recognize the Phenoms as supported processors.  OpenNebula will do everything I need and will run on the Phenoms, so that's what we are running.

OpenNebula supports a number of cloud storage approaches.  I decided on the Filesystem Datastore because of the simplicity of installation and operation.   There are 3 transfer modes available for the FileSystem Datastore:

• shared, images are exported in a shared filesystem
• ssh, images are copied using the ssh protocol
• qcow2, like shared but specialized for the qcow2 format

Since we are using QEMU/KVM as our hypervisor, and since it natively supports qcow2 and all of its features, I decided to use qcow2.  

One of the things about OpenNebula's shared data storage is that it appears to be pretty agnostic.  Most tutorials and documentation discuss NFS, however, I strongly suspect that I could use SMB, AFS, DFS, or any other network filesystems.   I may try that in a future blog post.  So it's the cluster builder's responsibility to create a working network filesystem independent of OpenNebula.  So you will want to get NFS working before you start with the OpenNebula install.