Spena

Q: Bootcamp Partition not Accessible After Resize of Mac Partition

Loner T, I've been struggling with a similar issue and hope you could help.  Through my research on this site it seems you've helped many and would like to benefit from your knowledge as well.

 

I'd like to be able to boot into Windows and can't do it.  Yes...I re-sized my Mac Partition using disk util, and my Bootcamp drive disappeared from the start up disk utility in System Preferences.  Here's the requisite information, please let me know if you need something else to further analyze. Thank you.

 

Last login: Wed Jun 24 16:52:44 on ttys001

franks-imac:~ frankmertes$ diskutil list /dev/disk0

/dev/disk0

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                        *500.1 GB   disk0

   1:                        EFI                         209.7 MB   disk0s1

   2:                  Apple_HFS Macintosh HD            61.8 GB    disk0s2

   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3

   4:       Microsoft Basic Data                         200.2 GB   disk0s4

 

franks-imac:~ frankmertes$ sudo gpt -r -vv show disk0

Password:

gpt show: disk0: mediasize=500107862016; sectorsize=512; blocks=976773168

gpt show: disk0: Suspicious MBR at sector 0

gpt show: disk0: Pri GPT at sector 1

gpt show: disk0: Sec GPT at sector 976773167

      start       size  index  contents

          0          1         MBR

          1          1         Pri GPT header

          2         32         Pri GPT table

         34          6     

         40     409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

     409640  120750376      2  GPT part - 48465300-0000-11AA-AA11-00306543ECAC

  121160016    1269536      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

  122429552  463234960     

  585664512  391108608      4  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

  976773120         15     

  976773135         32         Sec GPT table

  976773167          1         Sec GPT header

 

franks-imac:~ frankmertes$ sudo fdisk /dev/disk0

Disk: /dev/disk0 geometry: 60801/255/63 [976773168 sectors]

Signature: 0xAA55

         Starting       Ending

#: id  cyl  hd sec -  cyl  hd sec [     start -       size]

------------------------------------------------------------------------

1: EE    0   0   2 -   25 127  14 [         1 -     409639] <Unknown ID>

2: AF   25 127  15 - 1023 254  63 [    409640 -  120750376] HFS+    

3: AB 1023 254  63 - 1023 254  63 [ 121160016 -    1269536] Darwin Boot

*4: 07 1023 254  63 - 1023 254  63 [ 585664512 -  391108608] HPFS/QNX/AUX

franks-imac:~ frankmertes$

 

Screen Shot 2015-06-24 at 19.48.15.png

Posted on Jun 24, 2015 10:49 AM

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Q: Bootcamp Partition not Accessible After Resize of Mac Partition

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  • Helpful answers

  • by Loner T,

    Loner T Loner T Jun 24, 2015 11:20 AM in response to Spena
    Level 7 (24,596 points)
    Safari
    Jun 24, 2015 11:20 AM in response to Spena

    Please scroll down to the first MS Data entry and use 'P' to list files. Can you post a screen shot of the output that you see?

     

    Here is a table of the partitions with the first MS Data as your Windows partition.

     

    GPT 3 StartGPT 3 SizeGPT 3 EndNTFS StartSector OffsetNTFS SizeNTFS EndSector Offset (MB)NTFS(Gb)
    121160016126953612242955219376947271339920783003641976773112 34,834 373.365231

     

    Does the size look reasonable? The ~34GB gap is what you will lose in disk space.

  • by Spena,

    Spena Spena Jun 24, 2015 11:28 AM in response to Loner T
    Level 1 (0 points)
    Jun 24, 2015 11:28 AM in response to Loner T

    Screen shot as requested:

    Screen Shot 2015-06-24 at 20.24.29.png

    I don't mind losing 34 GB in disk space...that's reasonable.  Thank you.

  • by Loner T,

    Loner T Loner T Jun 24, 2015 11:32 AM in response to Spena
    Level 7 (24,596 points)
    Safari
    Jun 24, 2015 11:32 AM in response to Spena

    Hit Escape once (only) and go back to the previous screen. Scroll down to the MS Data entry that starts at 193769472 and use 'P' to list files.

  • by Spena,

    Spena Spena Jun 24, 2015 12:23 PM in response to Loner T
    Level 1 (0 points)
    Jun 24, 2015 12:23 PM in response to Loner T

    Screen Shot 2015-06-24 at 21.21.55.png

    Here you go...did I get it right?

  • by Loner T,

    Loner T Loner T Jun 24, 2015 1:02 PM in response to Spena
    Level 7 (24,596 points)
    Safari
    Jun 24, 2015 1:02 PM in response to Spena

    Yes, but can you scroll down and find the System Volume Information entry?

     

    It should look similar to the following.

     

    Testdisk-GoodWindowsPartition.png

  • by Spena,

    Spena Spena Jun 24, 2015 1:06 PM in response to Loner T
    Level 1 (0 points)
    Jun 24, 2015 1:06 PM in response to Loner T

    Screen Shot 2015-06-24 at 22.05.00.png

    Cautiously optimistic...

  • by Loner T,Solvedanswer

    Loner T Loner T Jun 24, 2015 1:16 PM in response to Spena
    Level 7 (24,596 points)
    Safari
    Jun 24, 2015 1:16 PM in response to Spena

    Install GPT Fdisk (aka gdisk).


    Leave your Testdisk display and start a new Terminal Window. You need to use the following steps. If you see any error messages during the following steps, please stop and post back here with the error message. The following steps have values from your Testdisk output (and you can verify) in Steps 7 and 8. Please notice the '+' sign in step 8 (this is called offset notation). The text in parentheses is for informational purpose to describe the action being taken. Gdisk has one-character commands except when entering numbers.

     

    Rebuild GPT4 using start/end offsets

     

    1. Sudo gdisk /dev/rdisk0
    2. P  (print the full list of parts)
    3. D  (delete)
    4. 4  (part 4)
    5. N  (new part)
    6. 4  (part 4)
    7. 193769472 ( - Start offset in bytes or the start point for Bootcamp part)
    8. +783003641 ( - Size offset, as opposed to End offset)
    9. 0700 (Windows part type)
    10. P  (print list of all parts just to see what changes will be made)
    11. W (Write the new GPT)
    12. Y  (Yes! really write the new GPT)

    This will delete and re-write the GPT partition info for /dev/disk0s4.


    Rebuild MBR to match the new GPT information thus resetting the Hybrid MBR. Use defaults for other questions (like partition codes). The only values that need modifications are the Boot flags and step 10. Accept all other defaults that Gdisk offers. Please see the sample Q&A as an example. These steps can be repeated if you make a mistake before you get to Step 12, otherwise start from Step 1 for these steps. Step 6 has numbers which are typed with a space between the numbers.

    1. Sudo gdisk /dev/rdisk0
    2. P  (Print list of parts)
    3. R  (Recover)
    4. O (print current Hybrid MBR)
    5. H (chooses Hybrid)
    6. Partitions numbers to be hybridized: 2 3 4
    7. Y  (Good for GRUB question)
    8. N  (part 2 boot flag)
    9. N  (part 3 boot flag)
    10. Y  (part 4 boot flag make NTFS bootable partition)
    11. O  (print current Hybrid MBR)
    12. W (Write the new MBR)
    13. Y (Yes! write the new MBR)
    14. Reboot

     

    Here is sample Q&A for this section. Please notice the Press Enter/Return.

     

    Place EFI GPT (0xEE) partition first in MBR (good for GRUB)? (Y/N): Y

     

    Creating entry for GPT partition #2 (MBR partition #2)

    Enter an MBR hex code (default AF): Press Enter/Return

    Set the bootable flag? (Y/N): N

     

    Creating entry for GPT partition #3 (MBR partition #3)

    Enter an MBR hex code (default AB): Press Enter/Return

    Set the bootable flag? (Y/N): N

     

    Creating entry for GPT partition #4 (MBR partition #4)

    Enter an MBR hex code (default 07): Press Enter/Return

    Set the bootable flag? (Y/N): Y

     

    Test 1 - Does Bootcamp Volume show up in Finder?

    Test 2 - Can you see files in Bootcamp Volume?

    Test 3 - Can you select Bootcamp in System Preferences -> Startup Disk?

    Test 4 - If Test 3 is successful, select Bootcamp and Click Restart.

  • by Spena,Helpful

    Spena Spena Jun 24, 2015 2:07 PM in response to Loner T
    Level 1 (0 points)
    Jun 24, 2015 2:07 PM in response to Loner T

    Success!  All four tests are a "go."  Wow...you have no idea how much frustration and work you just saved me.  I wish I possessed your level of understanding when it comes to MBRs, sectors, etc.  I'll have to go back and try to make some sense of what you guided me through.  Thank you again!

  • by Loner T,

    Loner T Loner T Jun 24, 2015 3:26 PM in response to Spena
    Level 7 (24,596 points)
    Safari
    Jun 24, 2015 3:26 PM in response to Spena

    This http://www.rodsbooks.com/gdisk/hybrid.html is an excellent resource if you want to read further. If both your OSes are working as expected, please backup both to separate external hard disks as a baseline for future recovery.

  • by Spena,

    Spena Spena Jun 24, 2015 3:45 PM in response to Loner T
    Level 1 (0 points)
    Jun 24, 2015 3:45 PM in response to Loner T

    Thanks for the resource and again for the help.