Removing an ESX host or stopping managing an ESX host?

We have heard some feedback that some of our customers did not expect VMM to remove an ESX host when a "Remove" action was requested for an ESX host managed through VirtualCenter Server (VC) by VMM Server. So, I think that it might be worth to talk about how exactly this works and how you could do what you intend to do on VMM:

• How it works:
  • Users can add a new ESX (that is not managed by any VC) through VMM's "Add Host" wizard or Add-VMHost cmdlet, and when the host is added to VMM, it's also added to the associated VC.
    • Note: We do require users to add at least one VC before users can add any ESX host.
  • Users can delete an existing managed (by VMM) ESX host from VMM, and when the host is deleted from VMM, it's also deleted (really deleted) from the VC that the ESX host is associated with.
• What you may want to do, if
  • if you want to delete the ESX host from VMware resource pool,
    • Delete it from VMM, so that the host will also be removed from VC and the resources on the host are taken out of the resource pool.
  • If you just want VMM to stop managing a specific ESX host that is added through VMM's "Add Host" wizard or auto-added when you added the VC,
    • Delete the VC that the ESX host is associated with from VMM.
    • Removing VC from VMM does not actually remove / destroy any VMware resources. It simply removes the information VMM Server knows about the VC and ESX hosts that are associated with this VC from VMM database.
    • Also note that when you remove the VC, all ESX hosts associated with this VC will also be removed from the VMM's view.

Hope this helps.

Thanks for reading,

Cheng