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Overview

This documenation describes a real-world virtualization lab by running Proxmox VE inside a VirtualBox VM, enabling a fully local environment for learning DevOps, infrastructure engineering, virtualization, and cloud concepts.

Proxmox & clustering — why it matters

Proxmox VE is a Debian-based, open-source hypervisor that runs KVM virtual machines and LXC containers, all managed through a web UI.

Benefits of clustering

  • Single control plane: manage multiple Proxmox nodes from one dashboard.
  • Live migration: move VMs between nodes with minimal downtime.
  • High availability (HA): automatically restart VMs on healthy nodes if a node fails.
  • Replication: scheduled syncing of VM data across nodes for fast recovery.
  • Scalability: add nodes to increase capacity without reorganizing your setup.
  • Better resource utilization: distribute CPU, memory, and storage load across the cluster.

When to use it

  • Learning DevOps, infrastructure, or cloud concepts.
  • Testing HA, migration, and replication workflows.
  • Running multi-node labs that mirror production operations.

Key trade-offs

  • Network and storage design become more important (latency, bandwidth, shared storage).
  • Cluster management adds operational complexity and requires monitoring.
  • Some features (e.g., HA, efficient replication) need reliable networking and proper fencing/qpinger setup.

Quick checklist to get started

  1. Ensure time sync (NTP) and reliable networking between nodes.
  2. Use separate networks for management, replication, and cluster communication.
  3. Configure fencing/qdevice or quorum helpers for safety in failure scenarios.
  4. Test live migration and replication in your lab before trusting production workloads.

Key components

  • Three computers or VMs with at least 6 GB RAM and 100 GB storage space per machine
    • Storage can be lower as we will be using dynamically allocated virtual disks
  • VirtualBox — host hypervisor that runs the Proxmox VM
  • Proxmox VE ISO — installed as the nested hypervisor inside VirtualBox
  • Ubuntu Server ISO — guest OS installed in a VM managed by Proxmox
  • Debian Server ISO — guest OS install in a VM managed by Proxmox
  • VBoxManage — CLI for creating and configuring the outer VirtualBox VM
  • Proxmox Web UI — dashboard used to manage the inner guest VMs

Lab architecture (my current setup)

  • AMD Ryzen 7 7800X3D
  • 32 GB RAM
  • 1 TB NVMe storage

Overview of what will be built

  • Server Template inside VirtualBox to clone
  • Installation Proxmox VE inside a VirtualBox VM clones
  • Configured networking so the Proxmox Web UI is reachable from the host browser.
  • Uploaded the Ubuntu Server ISO into Proxmox and created a guest VM.
  • Launched and installed Ubuntu inside Proxmox.
  • Resolved nested-virtualization KVM errors by disabling KVM for the guest.

Network configuration

  • Adapter 1: Bridge — outbound internet access.
  • Adapter 2: Host-Only — host ↔ Proxmox coresync network.
  • (Optional) Adapter 3: Host-Only — host ↔ Proxmox migration network.


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