Intalled High Sierra to High partition using Core.pkg. Booted to High and erased APFS partition with APFS file so guys we have a method to install mac os high sierra beta the seems to work, so post here your Then I delete apfs.efi driver and install High SIerra on HFS+ volume without the long wait. Best Video Software for the Mac How To Run MacOS High Sierra or Another OS on Your Mac Best Graphic Design Software the Mac Stay Safe with Best Free Password Managers.
Sorry you could not find anything on Seagate's site. Actually, for the Expansion Drive, according to that first link that I provided, there is no software available. Did you try to connect the drive to another USB port on the Mac Mini? Also, no matter where you connect it, can Disk Utility 'see' the drive at all? Also, in doing some searching about your drive model and High Sierra, saw this link: That actually indicates that the drive would need to be erased and formatted before it can be recognized. But I suspect you have a lot of important stuff on your drive, and thus Erasing it is out of the question. Sorry about so many links, but here is another one: Note one of them, where the user states: 'Actually, the screenshot you sent is exactly the one if you have not activated Show All Devices, but only the Show Only Volumes option in the View Dropdown (there are subtle differences.
For example, you wouldn't see Macintosh HD, but the drive denomination, and not the used quantity, but the smart status, etc). So, as I see it, Eau Rouge was the right path form start on. Has High Sierra introduced as default the view volumes only option? What for, to protect a user form himself who has found its way to disk utility?'
This link shows how to set the 'Select (All) Devices': Hopefully those links will help. I spent 3 hours on the phone to Apple and they had me try everything and in the end they said it was a Seagate problem. Seagate sent me about 20 emails to try things and even logged in remotely and then said it was an Apple problem,I have tried under a different user and terminal command can't see it,it was working with Sierra and it stopped working when I upgraded to High Sierra,I saw somewhere on the net that Apple had changed there file system in High Sierra to APFS and I think that's why it cannot see my expansion drive.