Good Linux question — answering as the UphillTech team:
You don't need to use sudo and su together-- su switches your user account (without arguments it switches you to root). sudo just elevates your privileges to root for the current command. It's reccomended to use sudo instead of su if possible, but to return to your normal account after calling su , simply use the exit command
Full answer by Paul: https://superuser.com/a/408992 (CC BY-SA 4.0).
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