I tend to back up my lightroom catelog folder periodically but after a hard reset trying to restore and then back up has been a nightmare.
In terms of my photos, I have 117k in my library and about 30,000 files in my catelog folder, split into the sub directories. most have long coded names, are tiny but take hours to copy to and from my NAS backup.... I am stating the obvious in that these are probably previews and smart previews etc but is there a way i can either just
A.) delete them with no impact
b.) clean them up so I dont have 30,000 catelog files?
In reality, you only need one or maybe two catalog files. I have one catalog that I keep all of my keeper images in, and another catalog that I call my "test" catalog that I use for experimenting. And that's it. I have each of those set to back up on a weekly basis. Occasionally I will go to the backup folder and eliminate all but maybe a half dozen backup files. Previews, smart previews, collections, keywords and all that other stuff is all stored inside of the catalog file. So if you really have as you say 30,000 catalog files, are these all backups of the same catalog? What have you done?