500GB with standard previews? That doesn't sound right to me, I have my catalog and full-size previews for 26,000 images on a 500GB drive and there's plenty of space. Are you sure you aren't referring to the photos themselves?
Anyway, yes you can move these items to the external HD. If these are NOT the photos themselves, you would move catalog and all associated previews to the external HD using your operating system, to the location/folder of your choice. Once everything is moved, double-click on the catalog file. Depending on the speed of the drive and the speed of the USB connection, you may notice that the catalog runs more slowly (or not)
Thank you! And yes these are the standard previews. I just retired and FINALLY have time to learn LR (have only been using PS) and to move my whole portfolio - now over 200,000 photos - ack - into LR! So I've already deleted the smart previews as I wouldn't have had any space left! (My actual photos are on several different HDs). So I just can move the whole LR folder that's right now in my "pictures" folder on my computer HD and move it with the operating system to an external HD - and LR will know where to get all the info it needs? Thanks again!!
Oh, 200,000 images ... that's different
One more question! Do I NEED to move the WHOLE LR folder (with the LR settings folder, etc)...or can I just move the "Lightroom 5 Catalog.lrcat" and the "Lightroom Catalop Previews.lrcat" folders??
Think I found that answer! THANKS!!
How do I move a catalog?
You can move your catalog to a different location on your computer's hard drive, to an external disk, or to another computer altogether. Simply use the Explorer (Windows) or Finder (Mac OS) to drag or copy the following files to the new location:
Notice that you're not moving any photos, nor are you moving the Lightroom application itself. If Lightroom can't find the catalog or your photos after you move a catalog, see Lightroom can't find my catalog. How do I find it? Or, My catalog can't find my photos. How do I find them?
- Catalog: [catalog name].lrcat
- Previews: [catalog name] Previews.lrdata
- Smart Previews (Lightroom 5 only): [catalog name] Smart Previews.lrdata
To transfer a catalog between a Windows computer and a Mac, copy your catalog, preview, and image files from the original computer onto a flash or other external drive. Then, attach that drive to the second computer and copy the files to the desired location on the second computer.
I think you should be computing minimal previews if you’re importing 100s of 1000s of photos, and just compute a folder or other selected subset of previews at a time if you’re going to work with those photos.