I have cloned the hard drive that my images are on to a more rough duty hard drive for traveling. Think of this as an additional back up. How do I direct LR to use that drive rather than the one it accesses typically? My plan is to back up/clone the traveling drive to the typical drive when I return home. The catalog resides on a MacBook Air that I'll use at all times. There just isn't enough space on the MB Air hard drive for the images. I thought to name the traveling drive with the same name as the drive that is at home, and that LR knows, but I think I'll get confused by doing that. The info on the both drives is identical at this point.
You use the Update Folder Location command, as explained in Part 2 of this document: http://www.computer-darkroom.com/lr2_find_folder/find-folder.htm
You might consider using Smart Previews instead of carrying the photos with you on an external drive, if you have the space.
Thanks so much! I tried it out and it worked perfectly.