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So what is the good procedure when we want to back up a wallet in order to transfer it to another computer or to upgrade our OS? Channels have to be closed necessarily? Or there is a way to "transfer" them too?
If you need to transfer it to another or upgrade your PC, you'll just have to copy the wallet file from the wallets folder in the data directory.
But make sure not to make a transaction on the original before opening the copied wallet, it's recommended to delete the old wallet after successfully loading the wallet to the new/upgraded PC.
There should only be one "
active" copy of your channel(s) or there'll be consequences if you accidentally spend from the outdated copy.
Using the backup option will just copy a "
static backup" of the channel to the backup wallet file where the only option is request to force-close.