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MacBook Pro bootcamp Windows cant see GPT partitions


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Hi guys, 

 

I have a problem with using windows 8.1 on mac

After I install the Windows via bootcamp I've split mac partition on three separated partitions but they are not visible from Windows.

 

  • 1) MAC OS (MAC OS EXT) GPT
  • 2) SHARED ETC (MAC OS EXT) GPT
  • 3) SHARED WORK (FAT) GPT
  • 4) WINDOWS 8.1 BOOTCAMP (NTFS) MBR

As far as I understand, after I googled around, Windows using virtual MBR on mac, and OS X using GPT and in my case they out of sync ?!

Correct me if i am wrong.

 

So I found that gptsync might help http://www.insanelymac.com/forum/topic/177505-enhanced-gptsync-tool

 

May be some one can advice if I am on right direction and how to use gptsync in my case to sync my MBR and GPT partition tables.

Or if there is other way to make GPT partitions visible form Windows.

 

The first Image (Windows Disc Management, with two partitions) is how partitions looks like when I booting Windows naively 

The second one is how partitions looks like in MAC OS Disk Utility

The third Image (Windows Disc Management, with more than two partitions) is how partitions looks like when I booting Windows using Parallels

 

here is my try:

 

gptsync /dev/disk0
 
Current GPT partition table:
 #      Start LBA      End LBA  Type
 1             40       409639  EFI System (FAT)
 2         409640    195722135  Mac OS X HFS+
 3      195722136    196991671  Mac OS X Boot
 4      196991672    587616655  Mac OS X HFS+
 5      587880448    782929919  Basic Data
 6      782929920    977104895  Basic Data
 
Current MBR partition table:
 # A    Start LBA      End LBA  Type
 1              1    782929919  ee  EFI Protective
 2 *    782929920    977104895  07  NTFS/HPFS
 
Status: MBR table must be updated.
 
Proposed new MBR partition table:
 # A    Start LBA      End LBA  Type
 1              1       409639  ee  EFI Protective
 2         409640    195722135  af  Mac OS X HFS+
 3      195722136    196991671  ab  Mac OS X Boot
 4      196991672    587616655  af  Mac OS X HFS+
 
May I update the MBR as printed above? [y/N] y
Yes
 
Writing new MBR...
MBR updated successfully!
 
After I check the result by booting WIndows using Parallels but still all the same.
So then I tried to boot Windows naively and no luck because windows MBR partition was vanished. ( 6      782929920    977104895  Basic Data)
 
Need help.

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Windows Legacy needs Hybrid MBR in GPT drive. Hybrid MBR ís limited to 4 partitions, while your drives has totally 5 partitions (including EFI), so 2 of 5 partitions will be seen as 1 partition, and both can't be accessed, so at best you can see 3 real partitions + 1 RAW partition in Windows. GPTSync can help you do this, but you will have no control of which RAW partition will be composed of. You can use gdisk from linux usb to manually create Hybrid MBR table, so you can create it like this:

Partition 1: EFI + MacHD

Partition 2: ETC

Partition 3: WORK

Partition 4: BOOTCAMP

 

You can format Windows Legacy and install Windows UEFI, convert Hybrid MBR to Protective MBR and it can see all the partitions. Find the guide for real Mac then.

I believe that my Windows already installed on Protective MBR(anyway I can check that?) and I remember when I boot it first I was able to browse MAC partition.(I had only single MAC partition on that time)

 

But after that I split up the MAC partitions to three partitions, so now Windows see them as one RAW.

Thats why I am trying to synchronize GPT and MBR. The partitions I want to be able to access from windows are 3(MacHD), 4(ETC) and 5(WORK).

 

Is there anyway to make it happened without reinstalling Windows?

The partitions I want to be able to access from windows are 3(MacHD), 4(ETC) and 5(WORK).

You cannot access all of them, you can only create 4 primary partitions (one should be used to protect the EFI) this way so decide which ones you need the most. Pokenguyen's suggestion is your best bet.

 

Is there anyway to make it happened without reinstalling Windows?

In the short term the best solution is to sync the MBR/GPT and keep Windows intact, but you'll lose access to one partition. At most you may need to run the installer to repair the boot sector.

 

In the long term you'll be better off creating a protective MBR and installing Windows in UEFI mode. This way windows will read the GPT and you won't need to do any stunt to access your partitions.

I believe that my Windows already installed on Protective MBR(anyway I can check that?) and I remember when I boot it first I was able to browse MAC partition.(I had only single MAC partition on that time)

Your Windows is Legacy (because it can't see all GPT partitions), and it can only be installed on GPT/Hybrid MBR. Only Windows UEFI (which reads GPT) can boot on GPT/Protective MBR. You can use gdisk to confirm this.

 

When you have 1 Mac partition, you only have 3 total partitions, so MBR can have record of all of them (MBR limit is 4 partitions). Now there are 5, so you only can have 3 real partitions + 1 RAW partitions (composed of 2 partitions).

  • 4 weeks later...

hi, this is my hard disk, and please let me know how to install GPT/Hybrid MBR.

 

 

windstoryui-iMac:~ cheolheehan$ diskutil list
/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *128.0 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                  Apple_HFS osx                     74.0 GB    disk0s2
   3:       Microsoft Basic Data startw8                 53.7 GB    disk0s3
   4:         Microsoft Reserved                         134.2 MB   disk0s4

windstoryui-iMac:~ cheolheehan$ gptsync /dev/disk0
ERROR: Can't open /dev/disk0: Permission denied

 

After this, I can see windows 8.1 boot menu, but I could not see clover  boot menu.

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