Migrating away from VMWare to ProxMox before its too late

The Curious Codex

          9 Votes   Published 2024-05-19, Updated 2024-06-16

Migrating away from VMWare to ProxMox before its too late

The Author

By Matt (Virtualisation)

Matt has been with the firm since 2015.


Migrating from VMware to Proxmox can seem like a daunting task, especially for a larger datacentres. However, with careful planning and execution, this transition can be smooth and beneficial. GEN DataCentres have been running a mixed environment with VMWare vSphere and ProxMox for about 10 years and we have extensive experience of both hypervisors. We took the decision to abandon VMWare and migrate all our VMWare hosts over to ProxMox at the start of the year, and for anyone else considering the same, we authored this article providing a comprehensive overview of the migration process, highlighting the key steps and considerations.

Why Migrate to Proxmox?


VMWare is in a state of collapse as Broadcam pillages its resources and its future is clearly uncertain. Proxmox, on the other hand is an open-source server management platform with a strong base and long term future. It combines the powerful KVM hypervisor and Linux container (LXC) technologies with a web-based management interface. Here are some compelling reasons to consider migrating:

  • Longevity: Moving hypervisors is a massive task, and no one wants to do it twice in their lifetime.
  • Cost Efficiency: Proxmox is open-source and free to use, significantly reducing licensing costs compared to VMware.
  • Flexibility: Proxmox supports both KVM and LXC, offering greater flexibility in managing virtual machines and containers.
  • Community and Support: Proxmox has a robust community and extensive documentation, with professional support available if needed.
  • Comprehensive Features: Proxmox provides integrated backup, live migration, and a user-friendly web interface.
  • API: Proxmox has a comprehensive API allowing easy integration with our systems and services.

Preparation Steps

Before starting the migration, thorough preparation is essential to ensure a smooth transition. Key preparation steps include:

Assessing Your Current Infrastructure

Conduct a detailed assessment of your current VMware infrastructure. Document all virtual machines (VMs) and processor requirements, storage configurations, network setups (Including MAC Addresses), and any dependencies. This assessment will help in mapping out the migration plan.

Migration Process

The actual migration process involves several critical steps. Here’s a step-by-step guide:

1. Setting Up Proxmox

Install Proxmox on new hardware. Follow the official installation guide to set up the Proxmox VE. Configure your storage, network, and any other required settings.

Connect ProxMox to your VMFS / NFS / iSCSI / SAN storage. ProxMox is debian so anything debian can do, proxmox can too.

2. Migrating Virtual Machines

You can use the following methods to migrate VMs from VMware to Proxmox:

  • OVF Export/Import: Export VMs from VMware as OVF files and import them into Proxmox. This method provides the highest chance of success.
  • Copy the VMWare storage .vmdk and then use convertdisk to convert this into a native ProxMox format. This requires a new VM to be created within ProxMox and then this converted storage attached.
  • Use ProxMox's built in VMWare converter, which is newly released but isn't yet perfect (May 24).

IF you're using VMWare Photon to host containers, as we were, then you must know that Photon does not run well in a ProxMox environment, but, since ProxMox supports containerisation directly, the better option here is to setup a Debian (or your chosen flavour of linux) as a container, then install docker, then migrate the docker containers over. Its a fairly simple process and has a fairly significant performance increase over running Photon as a VM and then docker on top of that.

3. Network Configuration

Reconfigure your network settings in Proxmox to match your existing setup. Ensure that all VMs have the correct IP addresses, MAC Addresses, VLANs, and other network configurations. In many cases Windows will require re-authorisation.

4. Testing

After migrating, thoroughly test each VM to ensure it is functioning correctly. Check for any performance issues or configuration discrepancies and address them promptly. Most Windows VM's will cope with the underlying hypervisor change, but some older Linux builds will have hard to resolve issues. In our experience, its sometimes easier, and more futureproof to simply build a new VM on the latest Linux platforms, then backup/restore the data from the VMWare VM to the new ProxMox VM. This was the chosen approach from our Virtualmin shared hosting clusters, and MariaDB Dataclusters.

5. Decommissioning VMware

Once you have verified that VMs are operating correctly on Proxmox, pull the VM from VMWare. Its worth keeping an image of these VM's on backup storage just in case you need to mount them up later down the road.

Post-Migration Considerations

After the migration, there are several ongoing tasks to ensure the stability and efficiency of your new Proxmox environment:

Guest Agents

Remove VMWare client software and install the qemu-quest-agent for ProxMox.

Monitoring and Maintenance

ProxMox doesn't have the same monitoring functionality that VMWare vSphere had, but its close, and with some SNMP additions you can get the same results. ProxMox is based on Debian Linux, so its update cycle is far more frequent than VMWare, so this needs to be incorporated into your schedueld maintenance routines.

Optimising Performance

Optimise your Proxmox settings for performance. ProxMox allows fine tuning of VM/LXC guests, so take the time to tweak these to get the maximum out of your resources.


For experienced VMWare technical staff, ProxMox is a completly different platform. Training in advanced ProxMox operations is essential to ensure technical staff can support your clients going forward.


Migrating from VMware to anything else is a significant undertaking but, many of us didn't have a choice. We chose ProxMox because we're experienced with it having operated it for many years, but what works for us, may not be the best for you, so do a through assessment before making a choice, this is a 5-10 year decision, so choose wisely.


GEN UK have been using ProxMox almost since its inception, we were early adoptors and have now migrated the entire estate to ProxMox. We can offer comprehensive ProxMox support and training services at very competative prices, so if you're going the ProxMox route, ask us for a quote.

          9 Votes   Published 2024-05-19, Updated 2024-06-16

--- This content is not legal or financial advice & Solely the opinions of the author ---

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