I'm kind of a novice here, and I think I got in over my head. I was trying to do a clean install of El Capitan on my 5K iMac. It has a 1TB Fusion drive.

I booted from a USB drive, entered Disk Utility, clicked the single partition I saw under the Fusion Drive, then erased it (pretty standard.. done this before). I was given some kind of error, then the partition disappeared.

Now, whenever I boot my computer and open Disk Utility, it looks like this:

No Fusion Drive partitions

No partitions under Fusion Drive. Clicking the Partition option doesn't give me any options (everything is greyed out and non-clickable). Clicking the First Aid option doesn't work either. It pops up a window asking if I want to Run or Cancel. Clicking on either does nothing. The window just sits there.

Like I said, I'm kind of a novice, so I don't know what to do from here. Any help, please!?

  • I should also mention that data loss is not an issue. Everything important is already backed up.
    – Branden
    Oct 6, 2015 at 3:13

1 Answer 1


Could you manually erase the drives via terminal, then recreate a fusion drive.

To manually erase the drives, go into terminal and do diskutil cs list. Then you'll need to do diskutil cs delete (lvgUUID). Here's more details: http://www.macworld.com/article/2015664/storage-flash/how-to-split-up-a-fusion-drive.html

After you delete it, you can recreate it: http://www.macworld.com/article/2014011/how-to-make-your-own-fusion-drive.html

  • Looks like the first step (erasing) wasn't necessary. But the second step (recreating) seemed to do the trick. Got everything reinstalled and it's working great so far. Thanks!
    – Branden
    Oct 7, 2015 at 5:19

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