Your real Monero and this test do not share a pile of files. Turning on --testnet makes a new folder called testnet next to your real chain. The real chain stays put. You can leave the test syncing there. Your normal node is already safe.
Move the folder only if you want the test files somewhere else, not because the real node is in danger.
The easy mistake is the folder name. The program always wants a folder named testnet inside whatever place you point it at. If you move the files and forget that name, it thinks you have nothing and starts the long download again.
Do it like this:
Stop the test node first. Do not move files while it is running. Make a new folder, for example fcmpBeta3. Put the existing testnet folder inside that, so the path ends in fcmpBeta3/testnet. Start the test node again and tell it the parent folder, fcmpBeta3, plus --testnet. Before October 5, a copy is just a spare, like photocopying your homework before the teacher writes on it.
Stop the node. Copy the whole testnet folder into fcmpBeta3/testnet. Copying one file is not enough. The folder has a lot of pieces. Start the test node again on the original folder. That copy is the one that should take the October 5 change. Do not open the spare with the beta program. If you do, it stops being a clean spare, and you may have to download the test chain all over again later.
Your real Monero and this test do not share a pile of files. Turning on --testnet makes a new folder called testnet next to your real chain. The real chain stays put. You can leave the test syncing there. Your normal node is already safe.
Move the folder only if you want the test files somewhere else, not because the real node is in danger.
The easy mistake is the folder name. The program always wants a folder named testnet inside whatever place you point it at. If you move the files and forget that name, it thinks you have nothing and starts the long download again.
Do it like this:
Stop the test node first. Do not move files while it is running.
Make a new folder, for example fcmpBeta3.
Put the existing testnet folder inside that, so the path ends in fcmpBeta3/testnet.
Start the test node again and tell it the parent folder, fcmpBeta3, plus --testnet.
Before October 5, a copy is just a spare, like photocopying your homework before the teacher writes on it.
Stop the node.
Copy the whole testnet folder into fcmpBeta3/testnet. Copying one file is not enough. The folder has a lot of pieces.
Start the test node again on the original folder. That copy is the one that should take the October 5 change.
Do not open the spare with the beta program. If you do, it stops being a clean spare, and you may have to download the test chain all over again later.