Hosts & Clusters 3.4
Clusters are pools of hosts that share datastores and virtual networks. Clusters are used for load balancing, high availability, and high performance computing.
A Host is a server that has the ability to run Virtual Machines and that is connected to OpenNebula's Frontend server. OpenNebula can work with Hosts with a heterogeneous configuration, i.e. you can connect Hosts to the same OpenNebula with different hypervisors or Linux distributions as long as these requirements are fulfilled:
/etc/hoststhe names of all the other Hosts and Frontend.
oneadminaccount in any Host or the Frontend should be able to ssh passwordlessly to any other Host or Frontend. This is achieved either by sharing the
oneadminaccross all the servers with NFS or by manually copying the
There are three components regarding Hosts:
onehostCLI command or through the Sunstone GUI. You can read about Host Management in more detail in the Managing Hosts guide.
oneclusterCLI command, or through the Sunstone GUI. You can read about Cluster Management in more detail in the Managing Clusters guide.
sshcommands in the host, but other mechanism are possible, name the Ganglia Monitoring System. There is further information on this topic in the Monitoring Subsystem guide.