When no more provisionable servers are available in the IDB, you will not be able to move a server from one server group to another in a single farm operation. Remove the server from the first server group and update the farm. Then add the server to the second server group and update the farm.
The server might be provisioned by another farm between removing it from the first server group and adding it to the second. Consequently a “no more resources” exception will occur.
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