Please, use </> button to share codes, terminal outputs, error messages instead of sharing screenshots. That helps others to search for similar issues and us to read it more easily and quote parts of the message so we can help you more quickly. You can find a complete guide in the following post: How to format your forum posts
Regarding the issue, if you mount a new disk to where the original data was, you will indeed lose the original data. If I misunderstand it and it is not what happened, please, explain what you did exactly.
Reloading the systemd daemon is neccessary only when you change the systemd service config and if you lose data after that, you either changed the docker data root or any other config like the storage driver that affects where Docker stores data.
The good news is that unless you deleted the original data, it is not likely that you actually lost data. Docker just doesn’t find it and uses a new folder.