Could you please let me know if the images are taking up space on the Hard Drive, or are the Catalog taking space on your computer.
If you could please explain more about the issue, it would be helpful.
I have transferred all of my images to an external drive. I also have pointed lightroom to start from a file on an external drive. The problem is that when I try and move my backup/catalog and other files to the external drive I get an error message. I have deleted about half of the back up files at this point. Is there a way to move lightroom completely off my laptop?
What error message do you get? Please quote the complete exact unedited word-for-word error message.
Exactly what exact files are you trying to move? Please be specific. "Other files" isn't particularly clear.
I couldn't tell you word for word, but when I went to close and back up it wouldn't let me until I moved the files back into my computer. Files include the catalog.ircat, ircat-journal, log.ircat.lock, backups, preview.irdata... My catalog is 697.88 mb. I've moved all the picture files off and I still need to make more room on my 8gb macbook pro retina with os x yosemite.
Sure you can tell us the error message word for word, you look at the error message, you write it down and then you type it in.
Or you can show us a screen capture.
Without this information, it's nearly impossible to help you.
Files include the catalog.ircat, ircat-journal, log.ircat.lock, backups, preview.irdata...
The presence of the journal and the lock file indicates that you are trying to the move the folder with Lightroom running.
That's not going to work. Close Lightroom, then copy the folder to the external drive.
Once you've got everything working, you can delete the original folder.
Because I moved everything back to my computer I am not getting an error message to show you. Can someone give me a step by step procedure to move it all off to an external drive and run it and back up it from an external drive ( including the changes I need to make in Lightroom preferences, etc.) ? Thanks!
It is not LR that is taking up all you HD space. It is the utterly stupid Temp backups Time Machine creates. They are called Local Snapshots and they are completely useless.
Take a look at this page for details.
Also to get rid of them open the Mac preferences then Time Machine and turn time machine off. Restart your Mac and then if you like you can turn time machine back on.