> If you only have run testnet then you have only the testnet blockchain so there is no data already downloaded that will be relevant to the mainnet blockchain.

Yes logical, but on that machine I wanted to start the mainnet I want to dedicate another one to the testnet, without having to redownload everything.

That machine is too slow for the various test experiments, so I wanted to designate it to the mainnet where experimental rubbish is done.

_Bubble_2009

bitcoin_beginners

BCT Full Node, switch from testnet to main

If you only have run testnet then you have only the testnet blockchain so there is no data already downloaded that will be relevant to the mainnet blockchain.  