Proxmox VE on a KVM VPS with nested virtualisation

Proxmox VE on a KVM virtual server

Proxmox VE is a hypervisor you run on a virtual server. Because OnionVPS uses true KVM virtualisation, the instance presents full hardware virtualisation to Proxmox, so it can host its own KVM guests and LXC containers. A container-based VPS shares the host kernel and cannot provide the nested virtualisation Proxmox needs. Know that Proxmox boots with a 4096 MB RAM minimum, but 16 GB is comfortable, and the hypervisor consumes a good chunk of that before any guest starts. Many providers disable nested virtualisation, so this works here and fails elsewhere.

People run Proxmox VE here to consolidate a home lab onto one IP, spin up nested test environments, and run reseller platforms with separate VMs or containers per tenant. The built-in backup and replication help, as does the web UI, but the heavy baseline resource use means you trade performance headroom for consolidation.

How much machine Proxmox VE actually needs

Plan for the operating system to cost you RAM before any guest runs. With a 4096 MB minimum, boot barely fits and leaves little for workloads. At 16 GB, you have roughly 12 GB for guests. Buy extra disk to accommodate ZFS and backups; start smaller than you think and scale up with extra RAM and NVMe.