Fix a Split Fusion Drive on Mac OS X - How-to for High Sierra and ALSO for Mojave and later

Apple shipped Fusion drives on some iMacs and Mac Minis in the past. It speeds up the drive by combining a fast, smaller SSD Flash Drive and a larger 1TB or bigger Hard Drive.
Sometimes the drives can be split by errors in formatting or crashes.
In this video we show you how to repair this problem and recombine your drives.
**MAKE SURE YOU HAVE A TIME MACHINE BACKUP BEFORE TRYING THIS**
Please Like, Comment, Subscribe and Share! We release videos often to help you get the most out of your Apple devices!
Let us know if the video helped you in the comments below! If you have any suggestions on topics we should cover, please also put them in the comments below.
Thanks for watching!
Commands you will need in this video:
To Fix in Mac OS X Mojave or Higher - diskutil resetFusion
To Fix in Mac OS X high Sierra or earlier:
- diskutil list
- diskutil cs create Name_Your_Drive diskx1 diskx2 (Disk “x1” is the SSD drive you found in “diskutil list”, Disk “x2” is the Hard Drive you found in “diskutil list”)
- diskutil cs list
- diskutil cs createVolume Logical “Volume Group Number” jhfs+ Name_of_Your_Drive 100%
- (You found this number “Logical Volume Group Number” above using “diskutil cs list”)
Fusion Drive is Apple Inc's implementation of a hybrid drive. Apple's implementation combines a hard disk drive with a NAND flash storage (solid-state drive of 24 GB or more) and presents it as a single Core Storage managed logical volume with the space of both drives combined.
The operating system automatically manages the contents of the drive so the most frequently accessed files are stored on the faster flash storage, while infrequently used items move to or stay on the hard drive. For example, if spreadsheet software is used often, the software will be moved to the flash storage for faster user access. In software, this logical volume speeds up performance of the computer by performing both caching for faster writes and auto tiering for faster reads. Basically this is just a regular SSHD because the technology and the functions are the same.
The Fusion Drive was announced as part of an Apple event held on October 23, 2012, with the first supporting products being two desktops: the iMac and Mac Mini with OS X Mountain Lion released in late 2012.[3] Fusion Drive remains available in subsequent models of these computers, but was not expanded to other Apple devices: the latest MacBook and Mac Pro models use exclusively flash storage, and while this was an optional upgrade for the mid-2012 non-Retina MacBook Pro discontinued by Apple, it will replace the standard hard disk drive instead of complementing it in the fashion of Fusion Drive. Supported products have the following configurations:
Mac Mini Late 2012 1 TB 128 GB
Late 2014
iMac
(all models) Late 2012
Late 2013
2014
iMac
(27-inch non-Retina) Late 2012 3 TB
Late 2013
iMac
(27-inch Retina) Late 2014
Mid-2015
iMac Late 2015 1 TB 24 GB
2 TB 128 GB
Mid 2017 1 TB 32 GB
2 TB 128 GB
3 TB
Early 2019 1 TB 32 GB
2 TB 128 GB
3 TB

[@joelhencken]

Superb teaching! I appreciate not only the information, but the calmness of your tone and the fact that you spoke slowly enough for me to take the information in! Many thanks!

[@chrisw7612]

Great sorted thanks, Big sur caused the split on update never thought it was simple to fix. Ps guys make sure you back up in more than one place incase you can’t get access to time machine files

[@MarkBanner]

Very easy to follow and the best version I have watched online.

[@christopherfawcett1260]

Wow thank you for this. On my 2015 iMac, I replaced my hard drive with an SSD drive so when I was at Apple today, they told me to just type in createFusion which didn’t work because my original OS was Sierra. So from recovery, your method worked. Thank you!

[@kashpatel9979]

Excellently explained and easy to follow, fixed my iMac 2017 retina model, starts and runs superb now. Many thanks!

[@davidrosillo86]

Big Thanks from Spain in 2020! Works great!

[@wintroy1]

I have the exact problem your help would be much appreciated. Randal

[@andrefelixstudio2833]

This is a great video, very well done and I was able to follow it, Thanks !

[@GemsbokAppleTipsandTricks]

Glad it helped!

[@Valadcm500]

You just save me a headache. Thank you!

[@apolosleon]

Thanks! It worked just fine!!!

[@zillomab7182]

First of all, thank you for your great explanation on how to fix a fusion drive.Let's say I want to upgrade the drives in the Mac mini late 2014 that came with a 1TB Fusion drive. For example, exchange the 128GB SSD to a 512GB SSD and the 1TB HD to a 2TB HD and create a Fusion Drive with the drives? Please, what is the specification for the SSD? Thank you in advance!

[@otronseverinbogni5522]

Hi Gents , Can I know why after install Mojave we can not have the list of core storage found by taping "diskutil cs list" ? Does Mojave broke core storage by installing ?

[@michaelmckoy6181]

Man I need some help when I do the Mojave version and type yes it ses aborted by user

[@chipset2900]

What please is the command to split/separate a fusion drive (mojave)?

[@mariozelada]

Will this erase the information on the hardrive?

[@miguelsamsung9662]

How do I fix the fusion drive? I won't allow me to update the IOS because it has errors and can't be formatted anymore. I took it to apple, and I was told they don't sell the part anymore. The rest of the computer is in excellent condition. Will this help me fix it?

[@Chad_Fuckhammer]

I just bought a refurbished mid-2011 iMac 27" and it looks like it only has 121.33 SSD. When I go into storage I see a non-clickable icon of a hard disk and underneath it it says 1TB and next to that to the right there is a long drive capacity bar with yellow on the far left side indicating space taken up by the operating system, etc and above the long bar it says 102.89GB available of 121.33GB. Why doesn't it say 1.1TB available of 1.12TB?

[@lenliz2003]

How do I reverse this process. I need my drives split as 2 separate drives.

[@Kuro-fj7jt]

Thank u man u r god

[@tantratron]

I own an iMac 27" late 2013 which I've replaced its internal HDD (1 To) by a Crucial SSD (2 To). It does have an internal SDD (128 Go) which was meant to work with HDD as Fusion drive technology. Is there any interest to now map or fusion drive two SDD's which are inside my iMac (pros and cons) ?

[@workingstoned]

Is there any way to combine without formatting? My fusion drive just split and I don´t have a backup of some of the files.

[@xdddre]

Came here to ask the same. Did you find the answer? My old Fusion Drive has split for no reason with all my files in it.

[@workingstoned]

@@xdddre I didn’t find any solution 😔 I ended up loosing most of my files. Lesson learned, always back up

[@ahsanrajjput3092]

How can I fix this problem

[@navigatorofnone]

Wonderful tip 👍👍👍

[@AM-od1yj]

Hi dude im new here First comment I hope you will be fine and you will see my comment and I’m a new subscriber and i have question when i Earse disk and Select format ApFs then They create disk container by default which take a lil bit space so how we will Reclaim it to main ssd drive or how we will remove it any method

[@giaanhvo542]

when i do the diskutil cs create it says diskutil does not recognize coreStorage verb "create" :(

[@GemsbokAppleTipsandTricks]

check all the spaces etc in the code. It needs to be exact, or you can get errors.

[@ahsanrajjput3092]

When I type yes there is showing operation aborted by user

[@joeking433]

I ran the diskutil in terminal and got this: diskutil resetFusion Internally-located hardware disk device known to the currently-running macOS: Rotational (disk0) Volumes exported by partitions or storage systems hosted on the above device: Untitled (disk2s1) mojave (disk3s1) Untitled (disk3s5) Your computer must have exactly 1 solid-state and 1 rotational disk drive What does that mean and what do I do now?

[@fmoiohnakaboylegang327]

I got exactly the same

[@ember5935]

aborted by user edit: I had the delete both the drives through recovery mode so i’ll see if this method works edit2: It worked thanks, now I can download windows10 again

[@Constipation_Think_Tank]

Dude, pick an operating system! Going back and forth gets confusing and time consuming.

[@thiagofraga8804]

Apple computers are so stupid.