So I have a 2015 5K iMac with a 1TB fusion drive in it. Today I attempted to install windows 10 using bootcamp but the installation froze and so I restarted the machine and erased the partition to try again. When I did this the partition went away but the other space did not come back so now my Mac thinks my hard drive is only 600 GB. I was on chat with Apple for a long time about this and the advisor had me enter in a bunch of commands in terminal to try to fix it but had no luck. I was told my only choice is to take it in to be repaired at an Apple Store. The closest one to my area is over 3 hours away so I'm hoping someone may have something else I can try before I have to make 2 trips over 3 hours.