Kirk, I've followed the link. I forgot the catalog, then located the existing catalog, then reintegrated under maintenance. The operation completed successfully, with the correct number of records, but local files found were 0, local files missing were 0, and files offline were the correct number that's on the old disk.
When I transferred everything to the new disk, I copied both the entire image folder structure and also copied the PM Catalogs. So what's apparently happening is that the catalogs are still looking for the files on the old disk, even though the image files themselves are on the new disk in the same folder structure.
Is there a way to tell the catalogs to look on the new disk instead of the old one? If that or something else doesn't work, am I back to deleting all the catalogs and rebuilding them from scratch as if this were a new PM install? I hope not, because that could take days since I've got over 14T of images. Surely others have had this new-disk problem, right?