We have one server running ESXi 6.7 for a 15-person company. It hosts three Windows Server VMs, including a domain controller and two business applications, plus an Ubuntu VM used for container testing.
The hardware was grant-funded, so replacing it may be difficult. Data is on a NAS, and we have 3-2-1 backups for the VMs and data. Would Proxmox be a sensible upgrade path, or should we consider something else?
Proxmox is a reasonable option for a setup this size, especially if someone on your team is comfortable administering Linux. You would be learning a different hypervisor, but you would also avoid relying on an ESXi upgrade path that may be too expensive for the business.
Check the server hardware and storage compatibility first, then test a migration before committing. In particular, verify what migration tools support ESXi 6.7 rather than assuming a workflow for newer versions will work. Also check that your backup software can protect and restore the VMs on the new platform.
Proxmox itself does not require a subscription. A subscription provides access to the enterprise repository and support, so decide whether that support is worth budgeting for in a business environment.
Give Hyper-V a look too. With three Windows VMs, your existing Windows Server licensing might make it a practical choice, particularly if your team is more comfortable with Windows administration than Linux.
Don't assume the licenses automatically cover the new setup, though. Check the host's core count, the Windows Server editions you own, and the virtualization rights for those licenses before comparing costs.
The missing piece is support. Who will troubleshoot the host when a business application is down, and how much time do they have to learn a new platform? A cheaper hypervisor isn't much of a saving if nobody can maintain it.
I'd compare Proxmox and Hyper-V against the hardware, storage, backup tooling and skills you already have. For four VMs, either could be workable, so familiarity and support may matter more than features you won't use.
Before picking a replacement, map out how the NAS connects and how the VMs use it. Storage and networking can work differently across hypervisors, and features you take for granted in ESXi may not have a direct equivalent in your proposed setup.
Check any storage multipathing, network configuration and snapshot requirements as part of the test. The VM count alone doesn't tell you whether the move will be straightforward.
XCP-ng is another option worth a look if you want alternatives beyond Proxmox and Hyper-V. Check its migration workflow against your ESXi version and hardware, then compare the support and learning costs rather than choosing on license price alone.
Answers are reviewed before publication.
a.37~pincushion:
Proxmox Backup Server is another backup option to evaluate, but I would test restores before retiring the existing backup workflow.