[phicoh]

I recently updated an old MacbookPro6,2 from Yosemite to High Sierra and that was a complete disaster. Took me a huge amount of time.

I think there two problems: the upgrade could not handle the way the disk was partitioned (or something else). Everything I tried kept failing until I removed the disk, and completely wiped it. Discussions I found online were not helpful.

The other part is the magic you need to download High Sierra on a newer Macbook. It is not as if you can just go to the Apple store and download it.

That said, I have been using Macbooks for work for the last 10 years or so. They always get upgraded a couple of times during their lifetimes. Usually not a big problem. So I was quite surprised how bad it went.

[chrisfinazzo]

High Sierra introduced APFS, so I'm not surprised you might have had formatting issues. Still, I wonder how common multiple partitions really are - among nerds, sure - in the broader userbase.