Apple Intelligence is now available on iPhone, iPad, and Mac!

⏺ Join the discussion

⏺ Press release 

⏺ Learn more

⏺ Watch the video

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

User profile for user: bobvader2001
bobvader2001 Author
User level: Level 1
0 points

2 Macintosh HD Partitions After Failed Bootcamp Partitioning

After 5 years of having the same iMac, I decided that it was time for an upgrade this Christmas. Long story short I now have a nice shiny new Retina iMac with a 3TB fusion drive. On my old Mac I had a Bootcamp partition of around 150GB of a 500GB hard drive. After having my new Mac for a few days now, I decided it was time to create a Bootcamp partition (500GB this time) so I could get some of the Windows only games to see how my new Mac handled them as my old one struggled to run Team Fortress 2 at over 15fps sometimes. I stared Bootcamp assistant and plugged in my previously written Windows 7 Pro 64-bit install USB, adjusted the slider and started the process. At first I was still trying to use the computer but with it beachballing every 15 seconds, that became very difficult. So, I turned on Caffeine so I didn't have to keep waking the screen back up and went and sat on my bed. After around 3 minutes, the screen started to dim (Caffeine should present this) so i went over to my computer and wiggled the mouse to bring the screen back. I then went back to my bed. After a short while, I noticed the screen had completely gone off. I though Caffeine was just being weird but when I tried to wake my computer, the screen was black (that sort of black when you know it's on but the screen is displaying black) with a beachball. I used CTRL and the left and right arrows to change spaces incase something had gone fullscreen. In the end to get the screen to display I would have to switch between dashboard and desktop 1 which had the Bootcamp assistant window in it. However, the screen wouldn't stay long enough for me to tell if the progress bar had moved. I also couldn't click or do anything. I left it about 20 minutes and it still hadn't resolved itself but was still 'partitioning the disk'. I decided to try and quit Bootcamp assistant with CMD Q but this just prevented the screen from even flashing up. I decided I had not choice but to brave shutting it down with the power button whilst it was supposedly still partitioning my hard drive. I checked Disk Utility and there were 3 partitions - 2 Macintosh HDs and a BOOTCAMP that was grey in the sidebar. I managed to remove the BOOTCAMP partition but I am now left with 2 Macintosh HD Partitions, one of 2.2 TB and the other of around 800GB. However only one partition displays under Macintosh HD in the sidebar but when you select that partition from the sidebar it says it is 2.31TB.


User uploaded file


I have restarted, verified and repaired my disk but still the same. DaisyDisk (3rd party) also only reads a 2.2TB startup disk called Macintosh HD. Unfortunately I'm at a loss here. I presume this isn't just how a Fusion Drive appears as I thought it was 3TB HDD and 128GB SSD. I would like to revert this incase of potential future problems so if anyone has any suggestions please let me know.

iMac with Retina 5K display, OS X Yosemite (10.10)

Posted on Dec 27, 2014 11:27 AM

Reply
10 replies
User profile for user: bobvader2001
bobvader2001 Author
User level: Level 1
0 points

Dec 27, 2014 12:41 PM in response to bobvader2001

So I tried removing with backspace in Disk Utility on both startup disk and Recovery, both give Alert (null) with a remove option which does nothing when clicked. In recovery mode, I looked at restoring a time machine backup and I could only restore the backup to the 2.2TB drive. When selecting a startup disk in recovery mode, only one partition shows up (I presume the 2.2TB) so the other appears to have a copy of all my data but not exist but still take up space (I've only used around 250GB of space)

Reply
User profile for user: JWDemon
JWDemon
User level: Level 1
5 points

Dec 31, 2014 10:21 PM in response to bobvader2001

That's an easy one, click on (select) the lower, smaller partition under Partition Layout and the minus sign below it will become active, click the minus sign and it will present a dialog asking if you're sure you want to remove that partition and erase all data on it, click Remove and the partition will be unified with the larger partition.


Don't be concerned with those EFI partitions in the diskutil list, those are hidden partitions used by the OS.

Reply
User profile for user: Fn77
Fn77
User level: Level 1
14 points

Jan 10, 2015 10:20 AM in response to bobvader2001

hi


have similar problem. somehow i cannot upload the screen grab (i get a size error even though it is only 400k), the only difference from the OP's issue is that get info on Macintosh HD returns the full 3tb of space, but disk utility shows 2 Macitosh HD partitions, 2.2tb and 800gb. All options and commands are greyed out (can't delete or create or change anything).


i have tried Disk Utility (also in recovery mode) but it does not help. neither does boot camp assistant (the problem originated from a botched bootcamp process).


looks like the OP solved the problem with a format from terminal. could anybody explain what that means and how i do that and then restore from a TM backup please? pretend you are talking to a neanderthal, simple words and short sentences!!


thanks

Reply
User profile for user: bobvader2001
bobvader2001 Author
User level: Level 1
0 points

Jan 10, 2015 11:13 AM in response to Fn77

Boot into internet recovery (Boot with option, shift and R held down I think - check that) and it comes up with a globe and takes a while to grab the recovery tools from Apple's servers. Then up the top: Utilities > Terminal


diskutil cs list

User uploaded file

Note: I have ended up with the problem again because the Windows installer I wrote to a USB was freezing instantly and I read somewhere that redoing the partition would help so I erased the partition (through bootcamp assistant this time) but I got the problem again so there seems to be a problem with Bootcamp if you've got the problem too. I'll have to restore again at some point but I've got Mock GCSEs starting Monday so it'll have to wait.


Then copy the highlighted UUID at the top to your clipboard.


diskutil cs delete <Paste UUID>


Let it run through that, shouldn't be long. When your see something similar to the bottom line it's done (I think it might say done as well but I can't remember).


After that you've got to quit terminal so the list of OSX utilities comes back up. Then go into Disk Utility and there may be some red writing (I think it may be only if it's a fusion drive but I can't be certain). Click fix and run through that, I seem to remember having to name the drive again (it gets renamed to Untitled in the terminal wipe) so I just named it Macintosh HD again.


Then erase the disk again from within Disk Utility from the top level drive. Let it wipe that (you may have to rename again. Can't remember)


Then once it's done that, exit out of Disk Utility so the OSX Utilities menu comes back up. You can either reinstall OSX (it re-downloads it as well so I wouldn't if you have slow internet like I do because it took about 4 hours to do) and then use Migration Assistant to restore your files from a backup OR just restore from a Time Machine backup straight away which still includes OSX but could be classed as not as clean but it worked for me just fine and is quicker if you have slow internet (only took about 1h 30)


I hope this helps :-)


If you need any further help just say but I won't be around until tomorrow now.


Matt

Reply
User profile for user: iW00
iW00
User level: Level 6
8,518 points

Jan 10, 2015 12:10 PM in response to bobvader2001

Starting up Mac to/from Internet Recovery, erasing HDD and Installing OS X again will result with installation of original OS that came on the mac. If your steps will be done on an older Mac which came with OS other than Yosemite, then this will only create some additional problems for somebody.


Before doing any operation on the HDD and its partitions, you should make a backup of your data: Mac Basics: Time Machine backs up your Mac - Apple Support


Also, if your Mac came originally with with different OS than is currently used, it is better to create a USB Recovery Disk which will give you an option to reinstall OS X which you are currently using:

OS X: About Recovery Disk Assistant - Apple Support

OS X Recovery Disk Assistant v1.0 - Apple Support

Alternatively: Create a bootable installer for OS X Mavericks or Yosemite - Apple Support


Next... If there is a problem with CoreStorage partitions, instead of using delete parameter it might be safer to use revert, as per man diskutil:

revert device | lvUUID [-stdinpassphrase] | [-passphrase passphrase] | [-recoverykeychain
file]
Convert a CoreStorage logical volume back to its native type. The volume must
have been created by means of conversion, e.g. with diskutil coreStorage convert.
If the volume was not created with a passphrase, then simple ownership of the
affected disk is required; otherwise, a passphrase must be supplied, either
interactively or via one of the parameters.
create | createLVG lvgName devices ...
Create a CoreStorage logical volume group. The disks specified will become the
(initial) set of physical volumes; more than one may be specified. You can spec-ify specify
ify partitions (which will be re-typed to be Apple_CoreStorage) or whole-disks
(which will be partitioned as GPT and will contain an Apple_CoreStorage parti-tion). partition).
tion). The resulting LVG UUID can then be used with createVolume below. All
existing data on the drive(s) will be lost. Ownership of the affected disk is
required.

This way, you not only have an option to correct your issue with HDD partitions but there is a chance that you won't have to install OS X again and restore your data.

Reply
User profile for user: Fn77
Fn77
User level: Level 1
14 points

Jan 24, 2015 8:56 AM in response to bobvader2001

took time but finally got round doing this. worked well with bob's solution (the alternative from iwoo was too complicated for my little understanding).


then i tried bootcamp again. froze during partitioning. computer restarted twice then stayed black screen. forced a re-start, bootcamp had partitioned but then failed to start windows installation. tried to delete bootcamp partition, this time through BCA, still same result with two Macintosh HDs...


at least i now know how to fix it, i think my mac does not like bootcamp!


Thanks for the help bobvader, hope all going well with GCSE

Reply

2 Macintosh HD Partitions After Failed Bootcamp Partitioning

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.
Learn more Sign up