iMac late 2013, Fusion Drive lost partition after BootCamp fail

frogurt2

macrumors newbie
Original poster
Jun 27, 2017
6
1
Hey everyone,

so, I had to use my iMac for a project and I had to install Windows on it to run some software.
Fired up bootcamp, downloaded all I had to, but once it restarted everything got stuck (I let it run for about 4 hours).
So I had to reboot it, and that's what probably caused the error.
Now I have reinstalled Sierra and everything works, but my Fusion Drive shows 3TB of space while my Macintosh HD shows 2.3, all those 700GB that were allocated for Windows are gone and aren't showing up in any partition.
I've run diskutil, here the results:

Screen Shot 2017-06-27 at 15.41.00.png


I don't care about files on it, so if any here can guide me step by step on how to solve this it would be greatly appreciated, I feel lost on macOS!
Best

edit: added picture for diskutil results
 
Last edited:

Weaselboy

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Staff member
Jan 23, 2005
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California
Do you have a Time Machine backup on a local (like USB) drive to work with?

That is the easiest option, otherwise we will need to use Internet recovery.

Let me know what you have and I can explain what to do.
 

frogurt2

macrumors newbie
Original poster
Jun 27, 2017
6
1
Do you have a Time Machine backup on a local (like USB) drive to work with?

That is the easiest option, otherwise we will need to use Internet recovery.

Let me know what you have and I can explain what to do.
Hey there, thanks for the reply!
unfortunately no backup available, I've formatted my iMac since it had all kind of junk in it, and didn't think much about backing things up.
So I guess I'll have to go the other way around! All I can count on is a usb stick and another machine (pc) at the moment :)
 

Weaselboy

Moderator
Staff member
Jan 23, 2005
29,144
8,813
California
Hey there, thanks for the reply!
unfortunately no backup available, I've formatted my iMac since it had all kind of junk in it, and didn't think much about backing things up.
So I guess I'll have to go the other way around! All I can count on is a usb stick and another machine (pc) at the moment :)
Okay... then you will need to do Internet recovery. Reboot and gold command-option-r at startup. Select your wifi and you will see a spinning globe as the recovery utility downloads.

Once the recovery screen comes up, go to the Utilities menu up to and launch Terminal. Now enter the line below exactly like I have it, including the quotes. That will wipe the Fusion drive.

Code:
diskutil cs delete "Macintosh HD"
Then follow my instructions in this post to rebuild the Fusion drive.

Once that is done, quit Terminal then click reinstall OS. That will get you back to the OS version that came from the factory. Once that is done you can Sierra from the App Store if you want.
 

frogurt2

macrumors newbie
Original poster
Jun 27, 2017
6
1
Hey there,

tried to run the delete command but I got this as a result:

Macintosh HD does not appear to be a valid Core Storage Logical Volume Group UUID or name

any idea on how to solve this?
thanks again for the reply!
 

Weaselboy

Moderator
Staff member
Jan 23, 2005
29,144
8,813
California
Hey there,

tried to run the delete command but I got this as a result:

Macintosh HD does not appear to be a valid Core Storage Logical Volume Group UUID or name

any idea on how to solve this?
thanks again for the reply!
Have you formatted or done anything since you did that "diskutil cs list" command in your first screenshot? Because I can see the Macintosh HD logical volume there. Did you include the quotes when you ran the delete command?
 

frogurt2

macrumors newbie
Original poster
Jun 27, 2017
6
1
No, did nothing at all as I've just got back at it :(
And yeah, included the quotes and everything as you said
Ran another diskutil cs list, here's the result:


Screen Shot 2017-06-28 at 15.33.48.png
 

Weaselboy

Moderator
Staff member
Jan 23, 2005
29,144
8,813
California
Hmm... try the delete command again with the logical volume group number instead of Macintosh HD. It will be that long string that starts with F50F972... there. No need for the quotes.
 

frogurt2

macrumors newbie
Original poster
Jun 27, 2017
6
1
Hmm... try the delete command again with the logical volume group number instead of Macintosh HD. It will be that long string that starts with F50F972... there. No need for the quotes.
Allright, that worked!
Followed your instructions in the other thread but something weird happened.
Before, if I ran disk utility from recovery mode, I had my fusion drive listed with 3TB and my Macintosh HD partition listed with 2.3TB.
Now I have my fusion drive listed at 2.31 and my new Fusion partition at 2.3.
If I run diskutil list from terminal I can still see the physical drive at 3TB though.
Did it fail to allocate 100% available space to the new logical volume?
I'm still in recovery, posting from mobile right now
 

Weaselboy

Moderator
Staff member
Jan 23, 2005
29,144
8,813
California
Allright, that worked!
Followed your instructions in the other thread but something weird happened.
Before, if I ran disk utility from recovery mode, I had my fusion drive listed with 3TB and my Macintosh HD partition listed with 2.3TB.
Now I have my fusion drive listed at 2.31 and my new Fusion partition at 2.3.
If I run diskutil list from terminal I can still see the physical drive at 3TB though.
Did it fail to allocate 100% available space to the new logical volume?
I'm still in recovery, posting from mobile right now
After you delete the Fusion and drive, and before you recreate it.... use Disk Util to erase both disks. When you do that, select the drive itself at the very top of the left column. That will format the drive back to one partition that takes the whole drive.
 

frogurt2

macrumors newbie
Original poster
Jun 27, 2017
6
1
Oh my, guess that's the bit I was missing,
WORKED LIKE A CHARM!

Thank you very much for your support and swift replies Weaselboy :D

Reinstalling os right now!
 
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