I support what was said above (external HD).
The beta I installed yesterday morning (and the previous I cannot
) does not want to be installed as is.
You have to install Sierra, then you will be able to install High Sierra. That is my experience.
Also, by default, my external High Sierra Hard Disk stayed as UFS+ (the format I use when I run Disk Util), it was not converted to APFS.
BTW: I started to install High Sierra on Monday and it tooks me 'till Saturday morning to be able to fulfill then install process.
Search an empty external hard disk, format it, download the High Sierra Beta and install it (after I install Sierra).
Also: it will take you time to do that (around 90 minutes to download Sierra, same time or so to install it, and same time to update it to High Sierra. Now you know that the used MBP will not be available to do anything else for a long time.
At last, I was amazed when I was able to run High Sierra
I do not knew what to do with it ! So, I power it down and do something else. I will be back to itin some days.
Once the boot proces is completely over, the OS is very fast (I spend only minutes, but it was my first feeling).
The whole installation takes 20 MB (around, at ± 1MB).
MBP 13", i3, 3 years old model.
Remember: running an application (for the first time ?) on High Sierra * will take some times the first time. After that, it will take (probably) the same time as in previous versions.
I hope I am crystal clear.
- I cannot use HS for High Sierra 'cause HS is short for Hors Service (Out fo Service in english ?) ;-