The question of "what to do with VMware" has ceased to be technical and become a budgetary one. Following Broadcom's acquisition, perpetual licences disappeared, products were merged into two bundles, and in April 2025 the minimum purchase requirement increased from 16 to 72 cores. A company with two eight-core servers now pays for 72, even if it actually uses only an eighth of them.

For a large enterprise, this is an unwelcome item. For a company with a single rack, it often becomes the reason to ask for the first time in years what is actually running underneath. The most common answer today is Proxmox VE - an open-source hypervisor based on Linux and KVM that can do the same thing on the same hardware without a licensing fee for the core.

What Proxmox actually replaces

A typical corporate environment using VMware utilises only a fraction of what the licence includes: virtual machines, snapshots, moving machines between servers and backup. Proxmox offers all of this too, live migration between nodes, snapshots, clustering and high availability, where a machine restarts elsewhere if one node fails. Additionally, it adds Linux containers, which are better suited for small services than full virtual machines because they incur only a fraction of the overhead.

The difference is noticeable in very large environments with hundreds of nodes and specific add-ons, there VMware still leads in tools that large teams are used to. For infrastructure consisting of units up to tens of servers, which covers most Czech companies, it is functionally a draw and a one-sided matter in terms of price.

How the conversion takes place

Migration is not a one-off switch but a series of small steps, each reversible. First, document what is actually running, which machines communicate with each other, which can briefly go down and which absolutely cannot. This creates an order: always start with the least critical to test the process where any potential issue causes no disruption.

Before the first intervention, a verified backup must exist: not an assumption that backups are made, but documented proof of a successful restoration attempt. Machines are then migrated one by one. Disks are converted to a format Proxmox can read, the machine is started on the new side, functionality is verified, and only then is traffic redirected. The original VMware environment remains untouched until everything runs as intended.

The most common snag is rarely with the discs themselves but with minor surrounding details: network cards receive different identifiers in the new environment, disrupting fixed IP addresses, and older Windows versions require additional driver installation after migration. Both are tasks taking minutes if anticipated in advance, or an unpleasant surprise at 3 a.m. If not.

What to check before you get started

Three things determine whether migration will be tedious or adventurous. First is the backup from which someone has actually tested a restore. Second is awareness of which applications have hardware-bound licenses: typically accounting and attendance systems, which may stop working after a change to the virtual environment until the supplier provides a new key. It is better to have this in hand beforehand than to seek support over the weekend.

Third is time. For smaller infrastructure with up to ten units, this typically involves several night windows rather than weeks. The volume of data and storage speed are decisive factors, as is whether planning includes a reserve or everything is squeezed into a single night.

When to postpone migration instead

If your licence is still valid for another year and the servers are at the end of their service life, it makes sense to combine both issues and address them together with a hardware refresh. Similarly, there is no point in migrating an environment that relies on a single unbacked-up server, this must be resolved first, because moving without a safety net is a gamble regardless of the destination. And if your application runs with a supplier who supports VMware exclusively, it is advisable to start with them rather than with the hypervisor.

Summary

The transition from VMware to Proxmox is now mainly addressed by companies for whom the cost of their environment no longer makes sense after consolidation into bundles and an increase in minimum consumption to 72 cores, especially when half of the features remain unused. Technically, this involves a series of reversible steps: analysis, backup, migration machine by machine, testing, and cutover. The risk does not lie with the disks but with surrounding details, network settings, hardware-bound licenses, and backups that have never been tested for restoration. More information on how we plan the entire transition is available on the page virtualisation and Proxmox.