Chosen Solution
MacBook Pro 15" Mid 2012 2.6GHz A1286 Why Can’t install MacOS High Sierra BETA on RAID 0 SSD setup ??? Here’s my MacBook config:
Update (10/13/2017) Thanks guys! It’s OK. I already unRAID’ed my SSD setup and sold off the second SSD. I’m just sticking to this config: MacBook Pro 15" 2012 non-Retina 2.7Ghz i7 Quad-Core A1286 16GB 2133mhz DDR3L RAM2TB SAMSUNG 850 EVO SSD2TB FIRECUDA SSHD
I had a thought! If you have a full backup lets give this a try: High Sierra offers a new file system APFS which is better for SSD’s. It also could be the answer here. But, to get there we’ll need to break the drive set so you can reformat the drives with APFS. Once you get both drives redone using an external boot drive go into Core Storage command line to recreate the RAID set. Then do an OS install. That should do it. Just remember! As @mayer stated this shouldn’t be your primary system. As if this fails you’ll need to roll things back!
Probably a bug in it. That’s what betas are for is to find these bugs and report them before a general release. See if there is an APP in your utility folder for reporting it to Apple. I also highly advise not using a beta version on anything other than a secondary drive - never replace your primary system with a BETA VERSION!
