Bootcamp – Can’t Reduce Size of OSX Partition

bootcampmacospartitionwindows

I'm trying to install Windows 7 Pro (64 bit) onto my new macbook air (OSX Yosemite 10.10.2). I'm using the Boot Camp Assistant and am at the point where it's asking me to create a partition for windows (with a slider). It won't let me reduce the Mac OSx partition smaller than 38 Gb. It currently says it's using 20 Gbs for OSx (18 Gb free), but I can't make it so that the MacOSx partition is only 20 Gb, which will give me more space for Windows.

Can someone please advise/tell me how to do this? or do I manually have to partition the drives and install Windows w/o using the bootcamp assistant.

Thanks

Edit: OSX Yosemite on a Macbook Air (Early 2014). After inputting "diskutil cs list", I get "CoreStorage logical volume groups (1 found)". I just received it last week so it's pretty new. Holding Cmd-alt-r-down took about 3 minutes to boot up. I do have an external flash drive (64 gb, exfat) and I don't use time machine.

I do not plan on upgrading/using the MacOSx, I just want to have it in case I need any warranty repairs (My coworker told me you need to have OSx installed for them to run diagnostics, else they won't touch your system).

Output:

CoreStorage logical volume groups (1 found)
|
 +-- Logical Volume Group 0415F924-645A-47A7-B045-936E0F0AAD94
     =========================================================
    Name:         Macintosh HD
    Status:       Online
    Size:         120473067520 B (120.5 GB)
    Free Space:   0 B (0 B)
|
+-< Physical Volume 536E4C17-EADB-4B7E-B71C-783BB62E2681
|   ----------------------------------------------------
|   Index:    0
|   Disk:     disk0s2
|   Status:   Online
|   Size:     120473067520 B (120.5 GB)
|
+-> Logical Volume Family 17DE7604-0810-4971-86F5-DDD56E0979AE
    ----------------------------------------------------------
    Encryption Status:       Unlocked
    Encryption Type:         None
    Conversion Status:       NoConversion
    Conversion Direction:    -none-
    Has Encrypted Extents:   No
    Fully Secure:            No
    Passphrase Required:     No
    |
    +-> Logical Volume 20593179-3E19-4A57-99D6-A713D13CE2FD
        ---------------------------------------------------
        Disk:                  disk1
        Status:                Online
        Size (Total):          120154296320 B (120.2 GB)
        Conversion Progress:   -none-
        Revertible:            Yes (no decryption required)
        LV Name:               Macintosh HD
        Volume Name:           Macintosh HD
        Content Hint:          Apple_HFS

Update 2: diskutil cs list now shows

 No CoreStorage logical volume groups found

but I still can't slide the bar Past 38Gb (19 Gb free) for the Mac Partition.

Best Answer

Update 2:

I assume OS X is installed on partition 2 of disk 0. If you want me to check this, then post the output of the next three commands and I will verify. Otherwise proceed and attempt the resize.

diskutil list
sudo gpt -r -vvv show -l /dev/disk0
sudo fdisk /dev/disk0

To resize to a smaller size, you will have to boot using OS X Internet Recovery. (Hold altcmdR at startup.) Open the Terminal application and enter the following command.

diskutil resizeVolume /dev/disk0s2 limits

Here is an example output. Your numbers will be different.

For device disk0s2 Steelhead:
        Current size:  345.1 GB (345131147264 Bytes)
        Minimum size:  35.3 GB (35299999744 Bytes)
        Maximum size:  345.1 GB (345131147264 Bytes)

Take the minimum size and use that in the next command. (i.e. replace 35.3 with your number)

diskutil resizeVolume /dev/disk0s2 35.3G

Hopefully this will resize to the smallest possible size.

Note: When testing this procedure, I did not use OS X Internet Recovery. My 2007 iMac is just to old. I had to use a flash drive to boot the OS X Recovery System. While you can also create and use a flash drive, I just assumed OS X Internet Recovery would be easier. You CAN NOT use the OS X Recovery System stored on your internal disk. If you want to try using the OS X Recovery System from a flash drive, you will need the OS X Recovery Disk Assistant v1.0.

Update 1:

Justin if you are afraid of violating the warranty, should I assume my answers should only be Apple approved? Well, that would just lead you to following the instructions that you have been already following. So, if that is as far as the slider will go then ... that is as small as you can make the OS X partition.

On the other hand, I would remove the Core Storage and then see if you can move the slider further. Why bother with backup anything up first. You are not going to use OS X anyway. The worst that could happen is you would have to reload from the internet. Your connection speed is fairly good, so that should not take long.

Of course, it would have helped to post more than the first line produced from the distutil cs list command. I assume you either misunderstood my instructions or are really bad at using OS X. I was hoping to determine if you had a Fusion drive and/or if Core Storage is revertible. Also, I believe you need the UUID to enter the command to revert.

If you choose to keep Core Storage, I would refer you to klanomath, he is far more experianced than me. (Actually, I have no experience with Core Storage other than reading his posts.) One of us could ask him for help, or at least, his opinion.

What is the model year of your macbook air? You can find this by clicking the apple icon on the menu at the top of your screen, then selecting "About this Mac". Also, you might as well determine if you are using core storage. To do this: Open the Terminal application and type the following command.

diskutil cs list

If the output is something other than

No CoreStorage logical volume groups found

then edit your question and post the results there. Don't worry about the format, I will clean it up for you.

I assume your Mac is new enough to boot off the internet. This is where you hold the keys cmd-alt-r down at startup. What I want to know is how long does that takes? Also, do you have any way to do backups. For example, do you have a external hard disk. If so, what format and how much free space. Or, do you use Time Machine? Finally, do you have another way to access the internet, other than your macbook air? If you can not add comments to my answer, the edit your question and post the answers there.

How to proceed, depends the answers to my questions. If possible I would backup your OS X partition. Then if you are using core storage, I would remove it. Core storage is only useful if you have a Fusion Drive. Next, if internet recovery is to slow, then I would transfer my Recovery partition to a flash drive. (You probably don't even know you have a Recovery partition hidden on your internal SSD.)

If you intend to leave OS X on your internal SSD and you are able to shrink to a size smaller than 38Gb, what happens when software updates need to be installed? Or, OS X 10.10.3 comes along? If you need to grow the OS X partition in the future, then the Windows partition will have to be removed to do so.

Related Solutions

MacOS – Unable to reformat/repartition CoreStorage logical volume (Fusion drive)

I was able to delete a mess I made trying to delete my Raid 10 in diskutil (which ended up looking similar to above) using the commands below in Terminal.app. May or may not work with fusion but it's easier than booting up again.

Get rid of the volume - copy paste the logical volume name where it says "Logical Volume Name", without the quotes:

diskutil cs deleteVolume "*Logical Volume Name*"

Free the disk - copy paste the volume name where it says "Physical Volume Name", without the quotes:

diskutil cs removeDisk "*Physical Volume name*"

Repeat these steps as needed.

Fusion Drive – Repairing Possible Mess-Up on 1TB iMac with BootCamp

Theoretically everything is fine with your Fusion Drive. Fusion Drives look like this. Disk0 is your SSD with 121 GB and disk1 is your HDD with ~1 TB (~1.121 TB summed up).

The larger parts of your SSD (disk0s2) and your HDD (disk1s2) are pooled to a CoreStorage LVG (Fusion Drive: disk3) with a size of 967.8 GB. The rest is reserved for EFIs, a Recovery HD (alltogether ~1.3 GB) and your old Windows partition - now probably free space (~152 GB).

The logical volume 'Macintosh HD' (967.8 GB) spans disk0s2 and disk1s2. This is the first 'Macintosh HD' in picture 1. The volume 'Macintosh HD' - it's the one visible on the desktop - should ideally also have about 967.8 GB. This is the second 'Macintosh HD' in picture 1.
In fact it has only 852.67 GB (see picture 3).

In the second picture the logical volume 'Macintosh HD' is the first listed in black, the volume 'Macintosh HD' is the second listed in black, the other two 'Macintosh HD's listed in grey are the parts of your SSD and HDD dedicated to the logical volume 'Macintosh HD'.

In my opinion something went wrong after deleting various partitions with the Bootcamp Assistant/Disk Utility or in Windows.

Preparation:

Detach any external drive (especially your external Time Machine backup drive)
Restart to Internet Recovery Mode by pressing alt cmd R at startup.
The prerequisites are the latest firmware update installed, either ethernet or WLAN (WPA/WPA2) and a router with DHCP activated.
On a 50 Mbps-line it takes about 4 min (presenting a small animated globe) to boot into a recovery netboot image which usually is loaded from an apple/akamai server.

I recommend ethernet because it's more reliable. If you are restricted to WIFI and the boot process fails, just restart your Mac until you succeed booting.

Alternatively you may start from a bootable installer thumb drive (preferably Mavericks or Yosemite) or a thumb drive containing a full system (preferably Mavericks or Yosemite).

Now you may either repair CoreStorage or rebuild your Fusion Drive:

'Repair CoreStorage' (not recommended):

First i would try to check the volume 'Macintosh HD' with Disk Utility. If the volume is corrupted consider a reinstall of Mac OS X.
If the volume is ok quit Disk Utility
Open Terminal and enter diskutil unmountDisk /dev/LVIdentifier and both diskutil unmountDisk /dev/DiskContainingApple_CoreStorageIdentifier
In your case: first diskutil unmountDisk /dev/disk3 then diskutil unmountDisk /dev/disk0 and diskutil unmountDisk /dev/disk1
remove the EFI NO NAME partition with gpt remove -i IndexNumberOfEFINoName DiskIdentifier:
gpt remove -i 4 disk1
Remount the CoreStorage disks and then the Logical Volume:
In your case: first diskutil mountDisk /dev/disk0 and diskutil mountDisk /dev/disk1 and then diskutil mount /dev/disk3.

enter gpt -r -vvv show /dev/diskIdentfierOfApple_CoreStorage to get infos of your HDD CoreStorage disk.
In your case: gpt -r -vvv show /dev/disk1
It should look like this:

-bash-3.2# gpt -r -vvv show /dev/disk1
gpt show: /dev/disk1: mediasize=1000204886016; sectorsize=512;         blocks=1953525168
gpt show: /dev/disk1: PMBR at sector 0
gpt show: /dev/disk1: Pri GPT at sector 1
gpt show: /dev/disk1: GPT partition: type=C12A7328-F81F-11D2-BA4B-00A0C93EC93B, start=40, size=409600
gpt show: /dev/disk1: GPT partition: type=53746F72-6167-11AA-AA11-00306543ECAC, start=409640, size=1671210848
gpt show: /dev/disk1: GPT partition: type=426F6F74-0000-11AA-AA11-00306543ECAC, start=1671620488, size=1269760
gpt show: /dev/disk1: Sec GPT at sector 1953525167                               
     start          size  index contents                                        
         0             1        PMBR                                            
         1             1        Pri GPT header                                  
         2            32        Pri GPT table                                   
        34             6
        40        409600      1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
    409640    1671210848      2 GPT part - 53746F72-6167-11AA-AA11-00306543ECAC
1671620488       1269760      3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
1672890248     280634887
1953525135            32        Sec GPT table
1953525167             1        Sec GPT header

The free space on your HDD has 280634887 blocks. Please calculate the biggest block number dividable through 8. That's 280634880 blocks (á 512 bytes) which equals 143685058560 B or ~143.7 GB. Add the size of your HDD CoreStorage Physical Volume (852666400768 B) The result is 143685058560 B + 852666400768 B = 996351459328 B
Resize your HDD CoreStorage physical volume with diskutil cs resizeDisk HDDPVUUID newsize
In your case: diskutil cs resizeDisk 93892BE8-2B7F-4ABD-A4C3-984495DCD98D 996351459328b
Calculate the maximal size of your CoreStorage Logical Volume in diskutil cs list: (size disk0s2) + (size disk1s2) In your case that's 120988852224 B + 996351459328 B = 1117340311552 B. That should be the size of your refreshed Logical Volume Group.
Resize your Logical Volume with diskutil cs resizeVolume LVUUID LVGSize-128 MB In your case that's diskutil cs resizeVolume D237FFDC-7DA4-41D7-AC13-4CC7E5E8C0A0 1117212311552b. If you get an error (There is not enough free space...) choose a smaller size like 1117148311552b.
Quit Terminal and open Disk Utility.
Check your expanded CoreStorage Volume for errors.
Quit Disk Utility, choose your CS volume as startup disk and restart your Mac

'Rebuild Fusion Drive' (recommended if you have a Time Machine backup)

Booted to Internet Recovery Mode open Utilities → Terminal in the menubar and enter:
diskutil cs list to get the CoreStorage listing.
Copy the Logical Volume UUID, it's the fifth listed.
Now delete the Logical Volume with diskutil cs deleteVolume LVUUID.
In your case: diskutil cs deleteVolume D237FFDC-7DA4-41D7-AC13-4CC7E5E8C0A0.
Copy the Logical Volume Group UUID, it's the first listed in the listing of diskutil cs list.
Then delete the Logical Volume Group with diskutil cs delete LVGUUID.
In your case: diskutil cs delete 1EFE58BC-3613-44C4-86EE-D816F3B66E3E
Enter exit and quit 'Terminal'
Open 'Disk Utility'. Enter 'Ignore' if you are asked to fix the drives.
Choose your SSD and partition it: 1 Partition Mac OS X Extended (Journaled), hit the Options button and choose GUID Partiton table and hit OK and Apply.
Please check that the size is ~121 GB

Example:
Choose your HDD and partition it: 1 Partition Mac OS X Extended (Journaled), hit the Options button and choose GUID Partiton table and hit OK and Apply.
Please check that the size is ~1 TB

Example:
Quit Disk Utility and open Terminal
Enter diskutil list

Example (your disk identifiers and sizes are different of course: Your volume SSD probably has the Identifier disk0s2 and the size 121 GB and your volume HDD probably has the Identifier disk1s2 and the size 1.0 TB):
Enter diskutil cs create "Name" IdentifierSSD IdentifierHDD
In your case probably diskutil cs create "Macintosh HD" disk0s2 disk1s2.

Copy the resulting LVGUUID

Example:
Enter diskutil cs CreateVolume LVGUUID jhfs+ "Macintosh HD" 100%.

Example:
Enter diskutil cs list
Check the size of your Logical Volume. It should have the size ~1.121 TB

Example:
Quit Terminal
Open 'Disk Utility' and check your newly created volume for errors
Quit 'Disk Utility'
Attach your external Time Machine backup drive or check this answer if you use NAS or another network share.
Open 'Restore from Time Machine Backup'
Choose the appropriate Time Machine backup and restore your system
Reboot to your restored system.
Unmount and detach your Time Machine backup drive
Open 'Terminal' and enter 'diskutil list'
Check if your 'Recovery HD' is listed.
If your 'Recovery HD' is missing, usually reinstalling your current system with the latest available system installer (e.g. 'Install OS X Mavericks (10.9.5)' if Mavericks is currently installed) will recreate it without loosing any data. AFAIK Recovery Partition Creator 3.8 will NOT create a Recovery HD on CoreStorage volumes.
After reinstalling the system with the latest available system installer open App Store and install the latest security fixes.

Best Answer

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Fusion Drive – Repairing Possible Mess-Up on 1TB iMac with BootCamp

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