Not able to prepare host in vCD? Remove the vCD agent....

When you try to prepare the host(s) you get below error,

The host is managed by another  vCloud Director system "vcd". Unprepare the host from the other system or uninstall the agent software on the host...

You will have to remove the vCD agent from the hosts. Whenever the host is prepared the vcloud agent is installed on the host to be managed by vCloud Director application. This error is because the agent is already installed on the host and was not removed correctly. We have to remove that agent from the hosts, and here is what we can do to achieve that,

Steps will follow the command line process,

1. First check and confirm if the agent is present on the host or not,

esxcli software vib list

2. Now run the removal command,

# esxcli software vib remove -n vcloud-agent --maintenance-mode

Removal Result
   Message: Operation finished successfully.
   Reboot Required: false
   VIBs Installed:
   VIBs Removed: VMware_bootbank_vcloud-agent_5.5.0-1280396
   VIBs Skipped:

Note: the option "--maintenance mode" in the command is so that you don't have to put the host into Maintenance Mode.

3. Check again using the command in step 1 if the agent is gone or not.

4. Prepare the host once again after the agent removal.

Alan Renouf has detailed a very hand way to remove the agents from large number of hosts, check here.