To perform Avantra transfer from one host to another please complete the following steps:
Install the Avantra master on the new system
STOP the master and the Avantra UI on this new installed server
Detach or dump the DB from the "old" Avantra Server
Transfer the data to the new server
Attach/restore the DB from the dump into the new Avantra Server
STOP the master and the Avantra UI on the "old" Avantra Server
Start the new Avantra Server (master and UI you stopped in the 2nd step)
Log into Avantra UI on a new server
Verify the Masterhost (go to Administration --> Settings --> Avantra master, check Network.masterhost) and the communication with the agents.