Proxmox server: the alternative to VMware

Why so many companies are leaving VMware

Broadcom closed its purchase of VMware at the end of 2023 and changed how it is sold: it stopped selling perpetual licences and bundled the products into subscriptions paid per processor core. For a small business with two or three servers, that has often meant paying a lot more for the same thing.

As a result, many companies are using their hardware refresh to change virtualisation platform as well. The alternative that comes up most among small businesses and public bodies is Proxmox VE.

What Proxmox VE is

Proxmox VE is an open-source virtualisation platform based on Debian. It runs virtual machines (KVM) and containers (LXC) and is managed from the browser: creating and moving machines, grouping them in a cluster, scheduling backups and enabling high availability.

There is no charge per core or per virtual machine.
The subscription is optional, paid per processor per year, and gives access to the enterprise repository and the vendor’s support.
It includes ZFS and Ceph storage, live migration between servers and a wizard to import machines from VMware ESXi.

Windows virtual machines run well with the VirtIO drivers. Note that Windows Server is still licensed the same way: the Standard edition covers two virtual machines per licence and Datacenter covers as many as you like on that server.

What hardware it needs

Proxmox does not ask for anything exotic, but it does need a well-sized server:

Processor: add up the virtual cores of every machine and leave headroom. Databases should not share cores with half the server.
ECC memory: what all the virtual machines use plus what ZFS uses as cache. With ZFS, the more memory the better.
Drives: mirrored NVMe for the virtual machines and high-capacity drives for files and backups. ZFS wants to see the drives directly, through an HBA controller, not behind a hardware RAID.
Network: 10 GbE if there is a cluster or shared storage.
Remote management: a dedicated KVM-IPMI to reach the console even when the system does not boot.

Indicative starting points for a Proxmox server
Case	Processor and memory	Storage
Office: 5–10 light machines	8–16 cores · 64 GB ECC	2 mirrored NVMe + drives for files
Mid-sized company: 10–25 machines	16–32 cores · 128–256 GB ECC	Mirrored NVMe or RAIDZ + separate backups
High availability	3 identical servers (or 2 and a witness)	Ceph or ZFS replication · 10 GbE network

If you also want local AI or remote workstations with graphics, Proxmox can assign a whole GPU to a virtual machine.

Backups with Proxmox Backup Server

Proxmox Backup Server makes incremental, deduplicated backups of the virtual machines, verifies them and can replicate them to another machine. Installed on a second server, or off site, it meets the 3-2-1 rule: three copies, on two media, one of them off site or offline.

A backup that has never been restored is not a backup: schedule a test restore every month.

High availability: when you need three servers

For a virtual machine to start on its own on another server when its host fails, the cluster has to be able to vote on which node is alive. That is why high availability needs three servers, or two and a small witness machine. The data also has to be in both places: with shared storage (Ceph) or with ZFS replication every few minutes.

For many small businesses one good server and well-made backups are enough: if it breaks, you restore. High availability pays off when a stoppage of several hours costs more than the second and third servers.

How to migrate from VMware

Proxmox includes a wizard that connects to an ESXi server and imports its virtual machines. The sensible approach is to migrate in batches: the least critical machines first, checking each one (VirtIO drivers on Windows, network, licences), and leaving the ones that cannot stop for last, outside working hours.

Hardware · tower and rackProfessional serversConfigured for virtualisation, files or AI, and tested for 24 hours before shipping.See →Guide · serversSmall business serverTower or rack, ECC memory, drives and RAID, and when a NAS is enough.See →Guide · Windows ServerWindows Server 2016 end of supportWhat to do before 12 January 2027 and how to migrate without stopping.See →Guide · local AIComputer for local AIWhich graphics card and how much memory you need to run models in-house.See →Guide · storageRAID in a serverRAID 1, 5, 6, 10 or ZFS: which to choose for your drives.See →Guide · serversRyzen, EPYC, Threadripper or XeonWhich server platform to choose for what it has to do.See →

Frequently asked questions

Is Proxmox free?

The software is open source and can be used without paying. The subscription is optional, paid per processor per year, and gives access to the enterprise repository and the vendor’s support. For a business we recommend having it.

Do Windows virtual machines run well?

Yes, with the VirtIO drivers. Windows Server is still licensed the same way: the Standard edition covers two virtual machines per licence and Datacenter covers as many as you like on that server.

Can I pass a graphics card through to a virtual machine?

Yes. Proxmox can assign a whole GPU to a virtual machine, which is useful for local AI or remote workstations.

How many servers do I need for high availability?

Three, or two plus a small witness machine that votes so the cluster knows which server is still alive.

Want to leave VMware?

Tell us how many virtual machines you run and what they do. We propose the server or the cluster at a fixed price in under 12 business hours.

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