After the update from Mojave to Catalina I noticed that the used disk space has increased from about 1TB to almost 2TB. And there is hardly any free disk space left.
A closer inspection of the file structure of the whole system shows that about half of the data is in the folder
/System/Volumes/Data/Previous Content/Users/myusername. It seems to be a mirror of my user data that was created during the upgrade. This would explain the sudden doubling of the disk space used.
I can't find any clear information about the purpose of the folder
/System/Volumes/Data/Previous Content/Users/ neither here in the forum nor on the web. Is it possible that after upgrading and setting up all user data from the backup, the contents of the folder
/System/Volumes/Data/Previous Content/Users/ can be deleted without problems? Since it does not seem to be necessary for the operation of Catalina?
(Note: this question is not about the general purpose of the APFS partition
/System/Volumes/Data/ of the new APFS)