Why can't I just put all KVM hosts into one big group? What is the purpose of a CloudStack Cluster?

CloudStack
1

A Cluster groups compatible hypervisor hosts that share common characteristics and primary storage.

For example:



Cluster A
 ├── KVM01
 ├── KVM02
 └── KVM03
       ↓
 Shared Primary Storage

Clustering helps CloudStack understand which hosts can work together for VM placement and operations.

When designing clusters, things like:

  • Hypervisor type/version

  • CPU compatibility

  • Storage configuration

  • Networking

  • HA requirements

need to be considered.