My configs and locations?

So am running my Calibre on Ubuntu and my drives are split up so I like to keep my library on mounted raid drives. I just let Calibre install in default location, but am guessing that means the cache and virtual library, configs, and any other items will grow larger on this smaller boot drive.

I understand about the environment variables per the documentation, but cannot figure how to set or change them. If I simply run , it does nothing. Help on this please from doing so via command line?

Additionally, I do have a client install on a Windows machine which also see thew library and all from the GUI, can I also adjust from there and if so, how?

Thanks in advance!