Migrating your entire virtual infrastructure from VMware ESXi to Proxmox VE 9 can sound daunting — especially when downtime isn’t an option. With VMware’s licensing changes under Broadcom in 2025, more organizations are moving to Proxmox VE, the open-source virtualization platform built on KVM, LXC, and Ceph.

But here’s the good news:
You can migrate hundreds of VMs from VMware to Proxmox VE 9 with little to no downtime — if you use the right techniques. This guide breaks down the best real-world methods used by IT professionals to ensure zero-downtime migration from VMware to Proxmox.

Why Zero Downtime Migration Matters

• Business continuity: Applications remain available throughout migration

• User transparency: No interruptions for employees or customers

• Controlled cutover: Switchover in seconds or minutes

• No dual-license costs: Avoid extended VMware licensing during migration

Understanding the Challenge

Since VMware ESXi and Proxmox VE run different hypervisors, you can’t do a direct “live migration.” However, you can achieve the same effect by pre-seeding data on the Proxmox side and performing a final sync or failover during cutover.

Top 5 Ways to Migrate VMware VMs to Proxmox VE 9 with Zero Downtime

1. Rsync / Disk Sync + Cutover (Best for Linux VMs)

This is the simplest and most reliable method for Linux-based workloads.

Steps:

1. Prepare Proxmox VE 9 VM shell:

   qm create 101 --name webserver01 --memory 4096 --cores 2 --net0 virtio,bridge=vmbr0


2. While the VMware VM is running, copy its disk in real-time:

   qemu-img convert -f vmdk -O qcow2 /vmfs/volumes/datastore/vmname.vmdk - | ssh root@proxmox "cat > /var/lib/vz/images/101/vm-101-disk-0.qcow2"


3. When ready for cutover:

   • Shut down the VMware VM

   • Run a final incremental sync (rsync or delta transfer)

   • Boot the VM in Proxmox

Downtime: Typically 1–3 minutes

Best for: Web servers, app servers, stateless Linux systems

2. Application-Level Replication (For Databases & Critical Apps)

If you’re migrating production databases, replication is your friend.

Example: MySQL or PostgreSQL

1. Deploy a new Proxmox VM with the same OS and DB version

2. Configure replication from the VMware-hosted database:

   • MySQL:

     CHANGE MASTER TO MASTER_HOST='old_vm_ip', ...;
START SLAVE;


   • PostgreSQL: streaming replication with pg_basebackup

3. Let replication catch up in real-time

4. At cutover:

   • Stop replication

   • Promote the replica to primary

   • Redirect traffic via DNS or load balancer

Downtime: 1–5 seconds (replication switch)

Best for: MySQL, PostgreSQL, Redis, MongoDB, MS SQL

3. ZFS Send/Receive (For Shared Storage Environments)

If both systems use ZFS, this is an extremely fast and reliable method.

Steps:

1. On VMware, export VM disks into a ZFS dataset.

2. Send dataset to Proxmox:

   zfs send tank/vm-001@snap1 | ssh root@proxmox zfs receive -F tank/vm-001


3. For incremental updates:

   zfs send -i @snap1 @snap2 tank/vm-001 | ssh root@proxmox zfs receive -F tank/vm-001


4. During final cutover:

   • Stop the VMware VM

   • Send last snapshot

   • Boot VM in Proxmox

Downtime: <1 minute

Best for: ZFS-based environments and fast SSD storage

4. Proxmox Backup Server (PBS) Incremental Migration

PBS can act as a bridge between VMware and Proxmox.

Steps:

1. Back up VMware VMs using Veeam or Restic to PBS storage.

2. Restore those backups directly into Proxmox VE 9.

3. Schedule frequent incremental backups to minimize final delta.

4. Perform the final restore and cutover.

Downtime: 1–2 minutes (final restore only)

Best for: Mixed environments and hybrid backup setups

5. Cold Migration (Fallback Option)

If live replication isn’t possible:

1. Schedule a short maintenance window

2. Shut down VMware VM

3. Export via ovftool

4. Convert:

   qemu-img convert -f vmdk -O qcow2 vm.vmdk vm.qcow2


5. Import and boot in Proxmox

Downtime: Full export/import duration (10–30+ minutes)

Best for: Legacy or test workloads

Pro Tips for a Smooth Cutover

• Use identical network names and VLANs on both systems

• Keep the same IP address and hostname — only switch routing/DNS

• Use load balancers to gradually redirect traffic

• Validate virtio drivers for Windows before boot

• Keep snapshots in VMware until full verification

Recommended Hybrid Strategy (For Large Migrations)

Combining these methods allows you to migrate entire VMware clusters with virtually no service disruption.

Final Thoughts

In 2025, Proxmox VE 9 stands as a mature, enterprise-grade alternative to VMware — offering flexibility, transparency, and scalability without licensing lock-ins.

By leveraging data replication, rsync pre-seeding, and final cutover strategies, you can migrate VMs from VMware ESXi to Proxmox VE 9 with zero downtime, no user impact, and minimal risk.

As enterprises modernize their infrastructure, mastering live or near-live migration to open platforms like Proxmox is the key to future-proofing IT environments.