VMware Tax
People will pay it once. I don't care for Proxmox, I despise the LVM silliness it sets up by default, I want a qcow2. You can do all of this manually, but I've been using qemu/kvm directly on linux with virtual manager, and it's just more straightforward. All that being said, we just migrated 32 branch machines from VMware -> Proxmox to avoid the new vmware tax. We are leaving our primary loads on VMW short term, but next move is the lower performance web facing stuff in our data center, that will probably drop behind an NFS or Gluster cluster.
Proxmox Data Center manager is kind of silly, the local web interface is pretty good, a little clunky on the nav side. Then again VMware is not the most intuitive interface either.
VMware just shot itself in the foot. It will maintain market dominance for a few more years, but without changing it;s licensing the myriad small players are all going to jump ship. 15% this year and every year after as people figure it out and migrate their workloads:
1. Create Ventoy boot on a large USB drive/stick
2. Re-format data partition as ext4, copy proxmox iso to it
3. Create NFS share via USB passthru device on a linux virtual guest
4. Mount share on VMware
5. Clone or move all your guests to the new USB storage
6. Reboot the box on the USB & install proxmox
7. Reboot, mount USB stick under proxmox
8. Build VM stubs for the guests
9 Import the guest vmdk's with 'qm' and attach to machines
10. Fire them up.
I scripted most of it
Windows versions we use only likes the older virtio driveres .182 or something .2xx doesn't fly. I added the VIRTIO driver disk to the data partiton with the proxmox iso, and imported it as well via script. Linux boxes just work.
Networking can get a little arcane, but if you need a trunk run the apprpriate 'qm' command on the guest interface.
Openvswitch is still a little unfriendly
Migrating to Libvirt/kvm/emu is equally easy, just use qemu-img to convert the vmdk's instead of proxmox's 'qm'.