Also, the blog said it's better not to put limits on volumes. So when I d/l another OS but want to keep the former one, how do I keep them in different volumes without one devouring the other (i.e.: I have Mojave and want to upgrade to Catalina and keep Mojave at the same time and separate.) The blog might have mentioned this but I can't keep it all straight for now.
Any volume may grow to occupy all the available space on the Container, but it cannot eat or use space that is already in use by another volume so if you have Catalina and Mojave installed on different volumes one cannot overwrite the other and both volumes would be full.
Originally Posted By: plantsower
Oh, I just create a volume and download Catalina to that one different volume, right?
Catalina will create a Container in its volume and that Container will have not one but three volumes,
an APFS Volume Group "Macintosh HD" consisting of
"Macintosh HD" a READ ONLY volume that contains the MacOS system and the MacOS standard apps such as Mail, Safari, Disk Utility, etc.
"Macintosh HD - Data" a read/write volume that contains all of your user files and data as well as third party applications
"Preboot" a small invisible volume used by the system when initiating startup
"Recovery" the invisible Recovery drive
Originally Posted By: plantsower
If I clean house and get rid of all of my old MacOS versions in my internal drive (SSD), how do I keep all the apps and utilities I have added to my old OS when downloading the new one?
Artie can speak for himself, but I don't believe either of us contemplated your "cleaning" your MacBook Pro's internal SSD.
Our, or at least my suggestion about "cleaning house" on your external drive asumed there was no unique data or applications on that drive or that anything on that drive is so antique as to present a potential danger to your current data. Therefore you would not lose anything of value by erasing that drive and starting over from scratch. If that is not the case then you have a long tedious task ahead sorting and moving all the critical data you want to conserve. That might be a good use for high capacity thumb drives or, even better, an SD card if you have a reader.
If you install Mojave on your internal drive converting that drive to APFS is optional but highly recommended, if you choose Catalina converting the drive to APFS is mandatory. In either case the conversion is non-destructive and all of your compatible applications, settings, and data will be left untouched. Any applications that are incompatible will be moved to a special folder and an alias to that folder will be placed on your desktop so you will know what has happened to them. (I had a few files show up when I installed Catalina and frankly I didn't know what any of them were nor have I detected anything not working 🤷â€â™‚ï¸) High Sierra, MacOS 10.13. can read data on an APFS drive but I don't believe it will install or run on APFS. Previous versions of MacOS cannot read or write to APFS volumes.
If we knew what it was we were doing, it wouldn't be called research, would it?
