It is possible to create a virtual cluster using the Proxmox hypervisor on top of an existing Proxmox cluster. Due to the performance drop with a nested hypervisor, the use cases of nested clusters are very limited. It can be used in the following scenarios, but is not limited to these scenarios:
Practice cluster in a classroom.
Test cluster to test latest software releases before applying to a real environment.
Proof of concept cluster to test new configuration ideas.
In this section we are going to see how to enable the nesting feature in Proxmox. Plan ahead if a nested virtual cluster is going to be used on a physical Proxmox cluster. There must be adequate resources, such as CPU and memory available, to support the actual and virtual nested cluster.
In order to have close to native performance of a hypervisor, the virtual machines must have access to some hardware features that leverage virtualization. These features are known as Hardware Assisted Virtualization Extension...