You can run a home DIY nostr:npub126ntw5mnermmj0znhjhgdk8lh2af72sm8qfzq48umdlnhaj9kuns3le9ll server on a used/spare desktop very easily. With just a couple clicks you can run a personal nostr relay on it that you can whitelist just your npub to. It is a way to have your own copy of all your notes.