I have some questions regarding how everything you do in lightroom gets backed up. By default LR does not write changes to xmp files. So what happens to any develop changes, keywording, rating; do they become part of the catalog? If you should have to restore a catalog in which metadata changes are not written to xmp, the restored catalog should restore all of your develop, keywording,rating, i.e metadata changes?
The reason I ask is because I had always been under the impression, perhaps mistakenly, that if you don't write these changes to xmp, then they are written to the original file which made me nervous, figuring anytime you write to the file you run the risk of corrupting it. But if LR is writing these changes to the catalog, then the original raw file remains untouched?
What happens if you convert to dng? Do the changes get written to the dng file or to the catalog?
I'm thinking that my understanding all of these years has been erroneous. Recently it has been pointed out to me that you take a hit in performance when writing changes to xmp. So if I have been wrong all of these years and if the LR changes are not written to the file but to the catalog, is there a way to safely get the data that sits in all of these xmp files in my harddrive into the catalog?