Merge Partitions on 2017 Imac 27"

[dago5252]

Hello all. I recently purchased a used 2017 iMac 27". The original owner wiped it clean but he did have windows installed with bootcamp. When I first booted the up & went through the set up I had 1.5TB .5 Tb allocated to bootcamp. SO I tried to install windows and accedentily created another partition which is now called untitled. So now it shows I have Macintosh has 990GB, Untitled 620GB & Untitled Data 620 GB. I tried to merge the free space, but keep getting errors. Is there a way to somehow get the HD back to factory specs without partitions?

Thanks

 

[Fishrrman]

"Fishrrman's way" to resolve partition problems is 100% guaranteed to do the job.

You will need an EXTERNAL drive large enough to hold the contents of the current Mac partition (unless you don't want to save anything on the drive).

You'll need CarbonCopyCloner, which is FREE to use for 30 days. Download it here:

Download CCC - Bombich Software

www.bombich.com

What to do next:
a. Use Disk Utility to erase the external drive to Mac OS extended with journaling enabled, GUID partition format (if you're going to use Mojave or Catalina, use APFS instead)
b. Use CCC to clone the contents of the existing Mac partition onto the external drive.
c. Now, BOOT FROM the external drive. Restart, and hold down the option key CONTINUOUSLY until the startup manager appears. Select the external drive with the pointer and hit return.
d. The Mac will boot from the external drive.
e. Open Disk Utility
f. Go to the "view" menu, and if you see the option to "show all devices", choose that. (If you don't see it, don't worry about it)
g. Now click on the TOPMOST item that represents the physical drive in the iMac
h. Click the ERASE button. What you do next depends on which OS you're using (you didn't tell us)
i. If it's High Sierra or earlier, choose Mac OS extended with journaling enabled, GUID partition format. If it's Mojave or later, choose APFS, GUID partition format
j. Once you've made your choice, follow through and erase the internal drive
k. Quit Disk Utility. The internal drive is now formatted as a "single Mac partition".
l. Open CCC and "RE-clone" the contents of the backup drive BACK TO the new internal partition you just created. This may take a while.
m. Before you restart, go to the startup disk pref pane and "re-designate" the internal drive to be the boot drive
n. Now, power down, disconnect the backup, then press the power on button.

If you get a good boot, log in and look around.
Things should be "where you want 'em to be" now...

 

[dago5252]

Thanks for the response. However, the erase option for the Fusion drive is greyed out. Should I chose the two untitled partitions to erase in step g?

Thanks
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Also, I am currently running Catalina.

 

[dago5252]

After following your steps, it did not delete the partitions. At this point, I am not sure it can be deleted. I also cannot merge the free space. Any other suggestions?

Thanks

 

[Fishrrman]

Hmmm....
Perhaps you need to "split" the fusion drive, erase the TWO drives (SSD & HDD) individually, then "re-join" them as a "new" fusion drive, then re-install.

I've never owned a fusion drive, so I'm not sure how the "erase" command may behave when trying to completely erase one.

One other thing:
Did you take the VERY IMPORTANT step (when booted into recovery) of going to disk utility's "view" menu and choosing "show all devices" ?

 

[dago5252]

Hmmm....
Perhaps you need to "split" the fusion drive, erase the TWO drives (SSD & HDD) individually, then "re-join" them as a "new" fusion drive, then re-install.

I've never owned a fusion drive, so I'm not sure how the "erase" command may behave when trying to completely erase one.

One other thing:
Did you take the VERY IMPORTANT step (when booted into recovery) of going to disk utility's "view" menu and choosing "show all devices" ?

Yes, I was able to view all devices/ Now all my work documents in Onedrive have been corrupted and will not open.