Mac Fusion Drive Split

  1. Remove Fusion Drive Mac
  2. Mac Fusion Drive Split Tool
  3. Mac Fusion Drive Split Tool
  4. Mac Fusion Drive Split File

2021/04/29 — Update: It’s 2021. IMacs are finally SSD. Internal SSD upgrades via Apple is a bit costly. Get an External HDD instead or setup a NAS. Use your money for RAM upgrades to 16. Here’s how I made a fusion Drive: Firstly I had to boot from the internet recovery partition. (Reboot and hold down Apple-R). I plugged in my Samsung T5 drive and combined with the internal SSD drive of the Mac Mini to form a new Fusion Drive. The Fusion Drive is blank so you then need to reinstall OS X onto it. This is how to Fix A Split Fusion Drive on any iMac that comes pre-installed with High Sierra or MacOS Mojave.Terminal Codes for MacOS High Sierra:disku.

Fusion Drive, a storage option on some iMac and Mac mini computers, combines a hard drive and flash storage in a single volume for improved performance and storage capacity. If your Fusion Drive appears as two drives instead of one in the Finder, it's no longer working as a Fusion Drive. This can happen after replacing either drive of your Fusion Drive, or using software to intentionally split them into separate volumes.

You can continue using the two drives independently, or follow these steps to regain the benefits of having the single logical volume of a Fusion Drive.

Before you begin

If you're not sure that your Mac was configured with a Fusion Drive, or that the drive has been split:

  1. Disconnect any external storage devices from your Mac.
  2. Choose Apple menu  > About This Mac, then click Storage.
    • If you see a drive labeled Fusion Drive, your Fusion Drive is working and this article doesn't apply to you.
    • If you have a Fusion Drive that has been split, you should see two drives. One of them should be labeled Flash Storage, with a capacity of 24GB, 32GB, or 128GB. The other should be at least 1TB.
Mac

Use Terminal to create a Fusion Drive again

These steps permanently delete all data stored on the drives that make up your Fusion Drive. Make sure that you have a backup before continuing.

If you're using macOS Mojave or later

Remove Fusion Drive Mac

  1. Turn on your Mac, then immediately press and hold Command-R to start up from macOS Recovery. Release the keys when you see the Apple logo or spinning globe.
  2. When you see the macOS Utilities window, choose Utilities > Terminal from the menu bar.
  3. Type diskutil resetFusion in the Terminal window, then press Return.
  4. Type Yes (with a capital Y) when prompted, then press Return.
  5. When Terminal indicates that the operation was successful, quit Terminal to return to the macOS Utilities window.
  6. Choose Reinstall macOS, then follow the onscreen instructions to reinstall the Mac operating system. Your Mac restarts from your Fusion Drive when done.

Mac Fusion Drive Split Tool

If you're using macOS High Sierra or earlier

Drive

Mac Fusion Drive Split Tool

  1. Turn on your Mac, then immediately press and hold Command-R to start up from macOS Recovery. Release the keys you see the Apple logo or spinning globe.
  2. When you see the macOS Utilities window, choose Utilities > Terminal from the menu bar.
  3. Type diskutil list in the Terminal window, then press Return.
  4. Terminal displays a table of data about your drives. In the IDENTIFIER column, find the identifier for each of the two internal, physical drives that make up your Fusion Drive. Usually the identifiers are disk0 and disk1. One of them should be 128GB or less in size. The other at least 1TB in size.
  5. Type the following command, replacing identifier1 and identifier2 with the identifiers you found in the previous step. Then press Return.

    Example: diskutil cs create Macintosh HD disk0 disk1

  6. If you get a disk unmounting error, enter diskutil unmountDisk identifier, using the first identifier you gathered previously. Then enter same command again using the second identifier. Then retry the command in step 5.
  7. Type diskutil cs list, then press Return.
  8. Terminal displays additional data about your drives (volumes). Find the string of numbers that appears after ”Logical Volume Group” for the volume named Macintosh HD. It's a number like 8354AFC3-BF97-4589-A407-25453FD2815A.
    Example:
    +-- Logical Volume Group 8354AFC3-BF97-4589-A407-25453FD2815A

    Name: Macintosh HD

  9. Type the following command, replacing logicalvolumegroup with the number you found in the previous step. Then press Return.

    Example: diskutil cs createVolume 8354AFC3-BF97-4589-A407-25453FD2815A jhfs+ Macintosh HD 100%

  10. When Terminal indicates that the operation was successful, quit Terminal to return to the macOS Utilities window.
  11. Choose Reinstall macOS, then follow the onscreen instructions to reinstall the Mac operating system. Your Mac restarts from your Fusion Drive when done.

Mac Fusion Drive Split File

Yesterday has been my best day so far in owning a Mac, so I thought I'd write it up for posterity..
Apple give users the option of buying a 'Fusion' drive when they buy a 2012 iMac or Mac mini. A Fusion drive is actually two physical drives within the machine. One of the drives is a small SSD (121GB usable), and the other is a standard HD with ~1TB usable. The advantage of an SSD is that it is realistically at least 5 times faster accessing files on the disk, but they are expensive and have comparatively little storage space. Normal HDs are cheap with lots of storage space, but they are much slower than SSDs.
Apple use a bit of arcane magic at file system level. These two drives appear as one drive to the operating system, and CoreStorage intelligently moves data around to get the best combination of speed and storage for the user. It works pretty well.
Except.. I wanted total control. I wanted a 128GB SSD, and a 1TB HDD visible to me, so that I had granular control of what went where.
An additional downside of Fusion is that you can only create one additional partition when you have a Fusion drive, and that extra partition HAS to be on the larger, slower HD. This means that a Windows Bootcamp setup will be much slower than a native OS X setup, because it's on the HD. This wasn't good enough for me either.
So off we go..
1) I cloned my OS X data to my external drive using SuperDuper!
2) I cloned my Windows partition to the same drive with WinClone
3) I updated my Time Machine backup as well.
4) I then booted into the clone and made sure all was good. It was.
I took a deep breath. The actual act of decoupling the two drives destroys the data on both of the drives AND my Windows partition. If my back-up regime was flawed, I was FUBARed.
I booted into my OS X Recovery partition and launched a Terminal. The super user prompt was blinking at me, and I smiled.
I followed the instructions in the following post.
http://www.macworld.com/article/2015664 ... drive.html
It took all of 30 seconds to type in both commands.
I ran Disk Utility, and sure enough there were now two distinct drives but they were highlighted in red - this I expected. So far so good!
I booted into my OS X backup clone, and formatted the SSD and HDD to be OS X journaled partitions. All was good! I then restored my SuperDuper backup to SSD, put the kettle on, and rebooted.
It was perfect. I had 45GB on my SSD, and nothing on the HDD. I then deleted some stuff from the SSD, and moved my iPhoto and iTunes library to the HDD. After pointing iPhoto and iTunes at their respective libraries. I now have 18GB of OS and Apps on my OS X SSD, and 22GB of media on my HDD. All is as it should be.
This was the end of part one of my day of geekery. I went and had a meal and a beer or two and came back and ran Bootcamp Assistant. I created a 61GB SSD partition for Windows. I then restored my Windows backup to the Windows partition.
WinClone worked flawlessly. Everything was exactly as it should have been. Running Windows 7 Pro from an SSD is awesome. 32GB RAM and an i7 also help, but the SSD is epic. My Windows experience index jumped from 5.9 to 7.7 so I'm happy with that!
Everything works, and SWTOR (and my iMac in general) has a whole new lease of life.
WinClone and SuperDuper are excellent pieces of software, and really kicked it out of the park for me. I really do believe in paying for quality software, and having the right tools for the job.
I think I earned my Mac stripes today!