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NervousFish2

macrumors 6502
Original poster
Mar 23, 2014
402
736
Dear all,

For reasons that aren’t necessary to get into here, I have a 2017 iMac that has its mechanical drive removed, and a Samsung EVO 850 installed in its place. I have been using the procedure discussed in the article linked below, to make a new fusion drive from the remaining NVMe, fusing it with the SATA SSD.

But I’m stuck on the following command.

diskutil coreStorage createVolume S87D6F8F-D9WJ-8AD9-SD88-VU89JI4FUI09 jhfs+ "Macintosh HD" 100%

The command works, and produces a HFS fusion drive. But I want an AFPS drive. So, some questions:

1. What should I put in the place of “jhfs+“ to make an afps drive?
2. Should I be making the drive journaled? Or even an encrypted afps drive at this point? If so, what would I insert in that line to do so?

When I tried to use the Disk Utility app, in recovery mode, to create the afps drive, I got an error. And the fusion drive disappeared. Or seemed to. All that was left was a container, which I could not create a partition on.

Apologies if these questions appear dumb or foolish but this isn’t really my area,

Thanks,

Nick

https://www.techrepublic.com/article/pro-tip-how-to-create-and-disable-a-fusion-drive/

UPDATE: Hmmm, I should have hesitated before posting the above. Turns out there may be another problem. After macOS goes thru the installation, and it boots for the first time, an message pops us that says “macOS can’t be installed on your computer”.... so, it’s not even working in HFS. But, I wonder, is this because the latest version of Mac OS wants to run on afps, if it’s a fusion drive?
 
Last edited:
1. What should I put in the place of “jhfs+“ to make an afps drive?

Currently macOS does not support APFS on fusion drives. Apple has promised such support will appear when macOS 10.14 appears (Mojave).

2. Should I be making the drive journaled? Or even an encrypted afps drive at this point? If so, what would I insert in that line to do so?

Your best bet right now is to do an HFS+ drive with journaling turned on. if you are concerned about security, you can then turn on Filevault for the drive once it is created.

HTH.
 
Currently macOS does not support APFS on fusion drives. Apple has promised such support will appear when macOS 10.14 appears (Mojave).

Your best bet right now is to do an HFS+ drive with journaling turned on. if you are concerned about security, you can then turn on Filevault for the drive once it is created.

HTH.

thank you - I was not aware of this. that is a very helpful clarification.

Well, now the only problem is to find out why macOS isn’t letting me install on the fusion drive, even in hfs+ format! Any thoughts on that? Seems odd.
 
Ok, I ran Disk Utility repair disk option, and reinstalled. It works! Now I have a fusion drive!
 
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