I'm running a node and my existing hard drive is running out of space. If I install a new hard drive, how do I move or point the node data to use my new hard drive instead?
You have 3 ways to do this
1) create a symlink from the previous location to the new location of the data directory. This way no change to your workflow is necessary
2) alternatively you can use the option
-d of the tezos node to point to the new data directory location
3) as suggested in the comments you can also mount the new disk at the old point after having synced all the data if your goal is to litterally swap disks and not keep the old one mounted at the old location.
For more details you can consult the official doc