CloudStack Clusters: The enablers of high availability and live migration in a Pod
A cluster is a logical grouping of identical hosts that enables live migration—the ability to move running virtual machines between hosts without any downtime. This single capability is what makes CloudStack (and modern cloud infrastructure) so powerful. What is a Cluster? A cluster is: Logical — a software grouping, not physical hardware Homogeneous — all hosts must run the same hypervisor (all KVM, all Hyper-V, etc.) Self-managed — CloudStack automatically schedules instances and migrations within the cluster Migratable — instances can move between hosts without stopping Where Clusters Fit Region └─ Zone (Typically = 1 Datacenter) └─ Pod (Usually = 1 Physical Rack) ├─ Cluster 1 (All KVM) │ ├─ Host 1, Host 2, Host 3 │ └─ Primary Storage │ ├─ Cluster 2 (All Hyper-V) │ ├─ Host 4, Host 5 │ └─ Primary Storage │ └─ Cluster 3 (All vSphere) ├─ Host 6, Host 7 └─ Primary Storage Notice: multiple clusters can exist in one pod, but each runs a different hypervisor type....