usb drive disapears overnight

[Dave Adam]

I tried reading some of the previous post about drives, but didn't find anything that worked.  If I missed one I'm sorry.

A couple of months ago I could live my computer on for weeks and my usb external hard drive would stay connected.  Now if I leave it sit for any length of time I have to hard boot my computer in order to get it to work again.  I feel like it is going to sleep or something, I can't even use terminal when this happens as it is all jambed up. And the restart function just goes to a blank page until I hard boot and start over.

I don't use my computer for a lot so I guess it's not an end of life thing, but it is anoying.

Any one have an idea what setting I need to change?

Thanks,