Clusters

A cluster consists of one or more logical grouping of Oracle Linux KVM hosts on which a collection of virtual machines can run. The KVM hosts in a cluster must have the same type of CPU (either Intel or AMD).

Each cluster in the environment must belong to a data center and each KVM host must belong to a cluster. During installation, a default cluster is created in the Default data center. For more information, see Clusters in the Oracle Linux Virtualization Manager: Administration Guide.

Virtual machines are dynamically allocated to any KVM host in the cluster and can be migrated between them, according to policies defined on the cluster and settings on the virtual machines. The cluster is the highest level at which power and load-sharing policies can be defined. Since virtual machines are not bound to any specific host in the cluster, virtual machines always start even if one or more of the hosts are unavailable.

Figure 4-2 Single Cluster


Single engine connected to a cluster with 3 VDSMs each connected to a Storage Domain.

Figure 4-3 Multiple Clusters


Single engine connected to a data center with 3 clusters.