Preparing your Fusion Drive Mac for the macOS High Sierra install?

>Why even let people with fusion drives convert to APFS in the first place?

To help test the betas, I'd presume, which are not meant to be convenient, or outright trustworthy, only test mules for those that wish to sample coming features, etc.

Here the same - unable to install the GM Release candidate. Please accept a APFS for installation .

Also for anyone trying this the instructions from Apple (linked above) are slightly incorrect.

sudo /Applications/Install\ macOS\ High\ Sierra\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume

• The intaller from the Mac App Store is actually "Install macOS High Sierra Beta.app" not "Install macOS High Sierra.app" as listed by Apple
• The Contents directory is actually "Contents" not "Content" as listed by Apple
• Not sure about this but the download location from the Mac App Store was "/Applications" not "/Volumes/InstallAssistant" as listed

Just a few things to check for anyone else needing / struggling with this.

I had this problem and eventually had to erase the internal fusion drive. Back up and running this late 2012 iMac and performance is excellent.

Plenty of backup here.

Really not impressive is it - I have an iMac that’s a few months old with a fusion drive, I am told how great the new file system is and so convert to it and can use early betas reasonably successfully (apart from the flashing folder scenario following hibernation as previously described ) then when gold master comes along it can’t be installed on current Apple hardware with the highly promoted new file system. I thought the whole point of having tight control over hardware and software was to ensure that it worked together. I would like to know if this is something that is going to be fixed soon or if all owners of fusion drives will have to stick permanently with the outdated file system. Also, publishing incorrect instructions to work around this - that’s just not professional!

It's even worse over here! I can't get my APFS Fusion drive back to HFS+ and I'm stuck... 😕

On point 8 https://beta.apple.com/sp/betaprogram/apfsfusionit says erase and format to "MacOS Extended (Journaled)", but all the options I get are 4 different APFS versions and nothing else. Did I overlook something? Can anyone help?

Thanks in advance!

Just posted this on another thread...

So I am in this position

If you installed a beta version of macOS High Sierra, the Fusion Drive in your Mac may have been converted to Apple File System. Because this configuration is not supported in the initial release of macOS High Sierra, we recommend that you follow the steps below to revert back to the previous disk format.

So I just went through the process by using the first option (creating a bootable USB drive) as listed here to revert back to MacOS Extended

https://beta.apple.com/sp/betaprogram/apfsfusion

The step for creating the bootable drive for me was...

sudo /Applications/Install\ macOS\ High\ Sierra\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/HighSierra --applicationpath /Applications/Install\ macOS\ High\ Sierra\ Beta.app

Followed all the subsequent steps - re-formatted the Fusion drive - converted from APFS back to MacOS Extended. Restored Time Machine backup only to find APFS was reinstated....back where I started!

Seems as if the installer re-instated the APFS...Maybe I picked the wrong High Sierra Beta installer?

I couldn't even choose the HFS+ (MacOs Extended) file format, only 4 APFS formats, this is bad...

So I eventually got this to work (after a few attempts)

The secret it seems is to create the bootable drive then remove the Installation file from the Applications directory

Using the beta GM candidate it seemed to re-format my drive back to APFS

Using the High Sierra Release - it would not Migrate the data - insisted I create a new user

Now have my Fusion Drive formatted macOS Extended (Journaled) and running High Sierra

Just cant mount my LaCie 5 Big 2 drive now...next problem

I tried Apple’s recommendation and made a bootable usb with High Sierra installation app for my iMac with fusion drive. Started installatio, was 99% done... and messa that failed and try again!

Apple... when can we expect a fix?

Thanks.

Booted from the web again opened Disk Utiity, I just used the Delete APFS volume botton in her upper left, got the warningn "Deleting “MBP HD” will delete all data stored on it, and cannot be undone." After that the the HD just disapeared. I quit and re-launched disk utility after which the HD (a 3TB Fusion) showed up as a " "container" but it showed up, I was able to choose it, formate as Mac OS extended and DONE!