TL DR-Upgrading from High Sierra to Catalina created a seperate partition for each on the hard drive and is now pretty much taking up the entire hard drive which causes time machine back ups to fail and need a way to consolidate the two partitions and remove the duplicated files. Is there a way for me to merge the two partitions so the files just consolidate themselves? Even through storage > manage storage, I can't touch any of the stuff in that High Sierra partition and I really don't want to have to build from scratch again :/ any advice is appreciated. So essentially almost the entire hard drive is taken up by the new Catalina partition and the old High Sierra partition as alot of stuff is doubled up between the two, even the core macOS files are on both partitions almost like you could dual boot the machine if you wanted. We took Mojave off and are now going to Catalina and for some reason when I upgraded my last good image from High Sierra up to Catalina it kept the entire High Sierra build as a separate partition on the hard drive.

I have never had an issue with this before and started doing this in El Capitan. Then all I have to do is some user specific settings after that. Then as I need to build a new machine I just install macOS and then import all of the settings from my time machine backup into the new build. So the way I build our Macs to not have to build from scratch every time is to build 1 Mac the way I want it, all the security settings set and apps installed then I make a full time machine back up of that machine. Our server/infrastructure teams do not really support a back end on imaging/supporting the few Macs we have at all. If you need help If you're having difficulty getting the links to work, try again using Safari. Follow the onscreen instructions to install macOS.

So I manage a relatively small footprint of Macs at our company, about 20. Open your Applications folder and double-click the macOS installer, named Install Version Name.

How to upgrade to catalina from sierra