11Oct 2019 Think Twice about Catalina Install

[Huntn]

Just to clarify situation this happened during downloading the update, not while it was installing. So it for some reason cut connections or something and download was cancelled but when I started it again it begin to download it from 0 and I could see hard drive space was still reserved by the failed one (about 4-5GB).

Anyway, second download was successful and it installed OK but I guess there is still a lot of garbage left as it shows there is about 20GB space possible to free in Disk Utility. Also I see in Disk Utility that there are just two "partitions" Macintosh HD and Macintosh HD - Data.
However as I'm newbie in MacOS and I've only used Mojave before this I was wondering how to actually access to Data? It automatically created desktop shortcut to Macintosh HD, but not to Macintosh HD - Data, so I'm unable to create new folder to root of that Macintosh HD like before? How to do that?
Also it created relocated items folder. Can I just delete it? There are only few files I recognize and I'll move them to HDD when I figure out how to create new folders there?

I guess I could try command that free disk space TM reserves for backups? Would this command work in Catalina too "tmutil listlocalsnapshotdates / |grep 20|while read f; do tmutil deletelocalsnapshots $f; done" ?

EDIT:
Yeah, that tmutil... command took care of that 20GB garbage. Now I have even more disk space than I had with Mojave. I was worried how well 128GB SSD would suffice with new OS but seems no problem.

Also I understand now more about that creating folders in root, it is not recommended anyway and it is prevented by default in Catalina. So I just move the stuff I wanted to save from Relocated Items folder to user folder and deleted the rest, so no Relocated Items folder anymore on desktop.

Until I come with a better method, I created a folder called Mac Sync in User/Documents where I keep the files I want on my MBP. This folder used to sit at the root level and is called Mac Sync because besides being backed up in Time Machine I keep it synced on two external hard drives that are mirrored with one another, so that’s 2 copies besides the original, and in addition to that I use iDrive and back that and other data to the cloud.
Time Machine is great for keeping a MacOS backups, but I’d never want to use it to back up a large volume of data.

 

[one more]

I have installed Catalina (10.15.1) on top of Mojave on Thursday. The installation itself went fine, but now my TimeMachine USB backup drive does not mount. The disc is connected, spins and flashes its lights as expected, but nothing appears in the finder, so I cannot actually backup at the moment. Any tips?