Just had an odd issue today.
A customer had created a Virtual Distributed Switch, but was unable to add his ESXi hosts to the vDS. It said that: “Host is not compatible with the VDS version.”
He was only able to join his version 6.5 ESXi host to a 5.5 vDS. If it was upgraded to version 6.0 or 6.5 it did not work.
There are multiple reports of this online related to upgraded hosts and vCenters. I suspect that it is an issue that you only run into if you do major upgrades without reinstalling ESXi, and since I never do that I have not had that problem before.
The quick solution to this problem is:
- Set host in maintenance mode (If possible. If not read on)
- Disconnect the host
- Remove the host from vCenter
- Add the host to vCenter
- Exit maintenance mode
You should be aware that this can have some consequences, but there are far less than a reinstall of the host which some suggest. I seems that the problem is with the vCenter database registration of the host, so maybe it would be possible to fix without this operations, but this was easy enough in this environment, so I did no further investigation.
If you have the possibility to evacuate all machine on the hosts that is the recommended approach, if not you can disconnect a host without moving the VMs, they will keep running, but HA and DRS will of course not work during this operation. You will also lose the VM folder and resource pool position of you VM’s on import, and possibly any VM Tags assigned to the VMs.
If you are using another distributed switch which is working, you will also have to rejoin that switch after you reconnect the host. If you do not know what you are doing, consult an expert.
Anything you see here is performed at your own risk.