I have a 5K Retina iMac. Its internal drive is an SSD.
It's not working. Let me explain.
I booted off an external drive.
When I look at the drive in the Disk Utility, there's no option to erase it.
When I look at the Partition tab, everything is grayed out.
When I click on Verify Disk, it says everything is good.
When I repair the disk it says it's all good.
The disk does not show up on the desktop.
Software cannot see it.
I want to format the drive. How?
Update: Problem solved in the Facebook thread.
Bonus: A video of me fixing the problem, in case you have the same thing wrong with your Mac fusion drive.