I can't remove a partition on my new iMac

In order to post an image click on the Camera icon in the toolbar of the message editor. When the dialog appears select the image you wish to post, then click on the Insert button.

The image you tried to post is not visible. I'm not sure what the condition of the drive is as of now. Am I to assume the smaller partition is the one you want to get rid of? In order to do this you must first boot the computer from the Recovery HD:

Boot to the Recovery HD:

Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.

After you open Disk Utility:

Select the drive's main entry (mfgr.'s ID and size) from the sidebar list. Click on the Partition tab in DU's main window. Then click in the rectangle of the smaller partition:

Both the Add [+] button and Delete [-] button buttons should be active. The Delete [-] button is not active in my image because that partition happens to be my boot partition.

You should be able to delete the partition.

You have one of the new fusion drive imacs, right. Well I have never worked on one but making a partition might of broken the fusion drive setup and there might not be a way to combine them back together.

I suggest you pack the system up and take it to a apple store and let them figure it out.

I would concur with LowLuster. You've done something to screw up the Fusion Drive configuration. Take it to an Apple retailer and let them sort it out for you.

The reason you have 2 drives named the same is because the top entry is the combination of both a ssd and a standard rotating drive in a logical storage volume. You need to go to apple.

See Mac mini (Late 2012) and iMac (Late 2012)- About Fusion Drive. I would also suggest a Google search for how to create a new partition and how to remove one from a Fusion Drive.

Open System Profiler in the Utilities folder. Select Serial ATA which will provide information on the HDD and SSD as separate entries on the right.

Well in one way consider yourself lucky, you got the fusion drive for the regular price. Now you have to go back to a apple store to get it straightened out.

There is a way for you to fix it. Do a google search on breaking up and making a fusion drive. There are several articles on it. The bad part is, even if apple does it, all your data will be wiped from the drives.

You must have a fusion drive or apple installed 2 1.5TB drives and then combined them into a logical storage volume to make it look like one 3TB drive. But I don't think there is enough room in the new imacs for 2 standard size HDD and there are no notebook size drives over 1TB.

I didn't even know apple offered a 3TB drive without fusion. I just checked and they do offer a 3TB standard drive. And the 3TB fusion is a extra $400, $250 over the upgrade you ordered.

I really don't understand how you could have a logical storage volume without the fusion option.

Go to about this mac then more info then system report. Look under serial ata. That should list all the drives in your system.

That is a Seagate 3 GB HDD.

Is that the only listing? That is a apple branded Seagate hard drive. So it is not a fusion drive. I have no idea why it was setup as a logical storge volume.

Was this ever figured out? I'm having the same exact issue now, down to the + and - keys being greyed out and the same 3TB seagate drive, and its very frustrating. Any help would be appricated