badseed76

Q: Is there a way to manually reassign a BSD Name to a drive?

Hello all,

 

I'm running a dual boot setup (via Bootcamp) and after initially setting everything up, had to temporarily setup another partition on the HD with my OS X and Windows/Bootcamp partition. Doing so seem to have reassigned my Bootcamp partition to disk0s4 which means that it now can not be booted into. My question is this, is there any means by which you can manually reassign BSD Names to drives and partitions? I'm fairly comforatble in the terminal so having to muck about in there to do so wouldn't put me off of any solution that required that. I'm really just hoping there a little more "elegent" a solution available other than getting rid of the Bootcamp partition and starting over from scratch with everything.

 

Thanks.

MacBook Pro, OS X El Capitan (10.11.3), 16GB RAM, 750GB HDD

Posted on Feb 20, 2016 12:13 PM

Close

Q: Is there a way to manually reassign a BSD Name to a drive?

  • All replies
  • Helpful answers

  • by Loner T,Helpful

    Loner T Loner T Feb 22, 2016 4:15 AM in response to badseed76
    Level 7 (24,202 points)
    Safari
    Feb 22, 2016 4:15 AM in response to badseed76

    If your MBP is prior to 2012, and/or you are running a BIOS/MBR Windows installation, creating a new partition on the GPT side, causes the GPT and MBR to be out-of-sync. This causes problems of Windows boot. The BSD disk name is only relevant on the OS X side. Windows just needs the MBR to be corrected.

     

    Can you post the output of the following Terminal commands?

     

    diskutil list

    diskutil cs list

    sudo gpt -vv -r show /dev/disk0

    sudo fdisk /dev/disk0

     

    The "sudo" commands will prompt for your password, and it will not be echoed back. You may also see a warning about improper use of "sudo" and potential data loss due to "abuse" of the command.

  • by badseed76,

    badseed76 badseed76 Feb 20, 2016 7:54 PM in response to Loner T
    Level 1 (10 points)
    Feb 20, 2016 7:54 PM in response to Loner T

    Hi Loner,

     

    Thanks for the follow up. here are the results of running the commands.

     

     

    diskutil list

    /dev/disk0 (internal, physical):

       #:      TYPE NAME                                      SIZE          IDENTIFIER

       0:      GUID_partition_scheme                    *750.2 GB  disk0

       1:      EFI EFI                                              209.7 MB   disk0s1

       2:      Apple_HFS Memnoch                       649.3 GB   disk0s2

       3:      Apple_Boot Recovery HD                 650.0 MB   disk0s3

       4:      Microsoft Basic Data BOOTCAMP    100.0 GB   disk0s4

    /dev/disk1 (internal, physical):

       #:     TYPE NAME                                      SIZE            IDENTIFIER

       0:     FDisk_partition_scheme                    *268.4 GB   disk1

       1:     Windows_NTFS Untitled                     268.4 GB   disk1s1

     

    diskutil cs list

    No CoreStorage logical volume groups found

     

    sudo gpt -vv -r show /dev/disk0

    gpt show: /dev/disk0: mediasize=750156374016; sectorsize=512; blocks=1465149168

    gpt show: /dev/disk0: Suspicious MBR at sector 0

    gpt show: /dev/disk0: Pri GPT at sector 1

    gpt show: /dev/disk0: Sec GPT at sector 1465149167

           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  1268158648      2  GPT part - 48465300-0000-11AA-AA11-00306543ECAC

      1268568288     1269536      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

      1269837824   195309568      4  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

      1465147392        1743        

      1465149135          32         Sec GPT table

      1465149167           1         Sec GPT header

     

    sudo fdisk /dev/disk0

    Disk: /dev/disk0    geometry: 91201/255/63 [1465149168 sectors]

    Signature: 0xAA55

             Starting       Ending

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

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

    1: EE 1023 254  63 - 1023 254  63 [         1 -     409639] <Unknown ID>

    2: AF 1023 254  63 - 1023 254  63 [    409640 - 1268158648] HFS+       

    3: AB 1023 254  63 - 1023 254  63 [1268568288 -    1269536] Darwin Boot

    4: 0C 1023 254  63 - 1023 254  63 [1269837824 -  195309568] Win95 FAT32L

     

    Some of this makes some sense to me, but a lot of it is, admittedly, a bit over my head. Any thoughts?

  • by Loner T,Helpful

    Loner T Loner T Feb 22, 2016 4:16 AM in response to badseed76
    Level 7 (24,202 points)
    Safari
    Feb 22, 2016 4:16 AM in response to badseed76

    1. You have a second HDD on your MBP, so I assume you have replaced your Optical drive. The second drive seems to be used for storage purpose.

    2. Can you post the output of

         sudo dd if=/dev/rdisk0s4 count=1 2>/dev/null | hexdump -C

        

         This will show the first block of the Windows partition.

  • by badseed76,

    badseed76 badseed76 Feb 21, 2016 3:38 AM in response to Loner T
    Level 1 (10 points)
    Feb 21, 2016 3:38 AM in response to Loner T

    1. That's actually just an SDXC card I still had plugged in, not an actual installed drive. Not sure if that matters, put figured I'd it it out there just in case.

    2. No problem, here it is:

    sudo dd if=/dev/rdisk0s4 count=1 2>/dev/null | hexdump -C

    00000000  eb 52 90 4e 54 46 53 20  20 20 20 00 02 08 00 00  |.R.NTFS    .....|

    00000010  00 00 00 00 00 f8 00 00  3f 00 ff 00 00 30 b0 4b  |........?....0.K|

    00000020  00 00 00 00 80 00 80 00  ff 1f 96 0b 00 00 00 00  |................|

    00000030  00 00 0c 00 00 00 00 00  02 00 00 00 00 00 00 00  |................|

    00000040  f6 00 00 00 01 00 00 00  c2 6d ab 24 86 ab 24 90  |.........m.$..$.|

    00000050  60 34 b4 7c fa 33 c0 8e  d0 bc 00 7c fb 68 c0 07  |`4.|.3.....|.h..|

    00000060  1f 1e 68 66 00 cb 88 16  0e 00 66 81 3e 03 00 4e  |..hf......f.>..N|

    00000070  54 46 53 75 15 b4 41 bb  aa 55 cd 13 72 0c 81 fb  |TFSu..A..U..r...|

    00000080  55 aa 75 06 f7 c1 01 00  75 03 e9 dd 00 1e 83 ec  |U.u.....u.......|

    00000090  18 68 1a 00 b4 48 8a 16  0e 00 8b f4 16 1f cd 13  |.h...H..........|

    000000a0  9f 83 c4 18 9e 58 1f 72  e1 3b 06 0b 00 75 db a3  |.....X.r.;...u..|

    000000b0  0f 00 c1 2e 0f 00 04 1e  5a 33 db b9 00 20 2b c8  |........Z3... +.|

    000000c0  66 ff 06 11 00 03 16 0f  00 8e c2 ff 06 16 00 e8  |f...............|

    000000d0  4b 00 2b c8 77 ef b8 00  bb cd 1a 66 23 c0 75 2d  |K.+.w......f#.u-|

    000000e0  66 81 fb 54 43 50 41 75  24 81 f9 02 01 72 1e 16  |f..TCPAu$....r..|

    000000f0  68 07 bb 16 68 52 11 16  68 09 00 66 53 66 53 66  |h...hR..h..fSfSf|

    00000100  55 16 16 16 68 b8 01 66  61 0e 07 cd 1a 33 c0 bf  |U...h..fa....3..|

    00000110  0a 13 b9 f6 0c fc f3 aa  e9 fe 01 90 90 66 60 1e  |.............f`.|

    00000120  06 66 a1 11 00 66 03 06  1c 00 1e 66 68 00 00 00  |.f...f.....fh...|

    00000130  00 66 50 06 53 68 01 00  68 10 00 b4 42 8a 16 0e  |.fP.Sh..h...B...|

    00000140  00 16 1f 8b f4 cd 13 66  59 5b 5a 66 59 66 59 1f  |.......fY[ZfYfY.|

    00000150  0f 82 16 00 66 ff 06 11  00 03 16 0f 00 8e c2 ff  |....f...........|

    00000160  0e 16 00 75 bc 07 1f 66  61 c3 a1 f6 01 e8 09 00  |...u...fa.......|

    00000170  a1 fa 01 e8 03 00 f4 eb  fd 8b f0 ac 3c 00 74 09  |............<.t.|

    00000180  b4 0e bb 07 00 cd 10 eb  f2 c3 0d 0a 41 20 64 69  |............A di|

    00000190  73 6b 20 72 65 61 64 20  65 72 72 6f 72 20 6f 63  |sk read error oc|

    000001a0  63 75 72 72 65 64 00 0d  0a 42 4f 4f 54 4d 47 52  |curred...BOOTMGR|

    000001b0  20 69 73 20 63 6f 6d 70  72 65 73 73 65 64 00 0d  | is compressed..|

    000001c0  0a 50 72 65 73 73 20 43  74 72 6c 2b 41 6c 74 2b  |.Press Ctrl+Alt+|

    000001d0  44 65 6c 20 74 6f 20 72  65 73 74 61 72 74 0d 0a  |Del to restart..|

    000001e0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|

    000001f0  00 00 00 00 00 00 8a 01  a7 01 bf 01 00 00 55 aa  |..............U.|

    00000200

     

    I can post a screenshot if this formatting is a little too wonky to make heads or tails of.

     

    Thanks.

  • by Loner T,Solvedanswer

    Loner T Loner T Feb 21, 2016 7:36 AM in response to badseed76
    Level 7 (24,202 points)
    Safari
    Feb 21, 2016 7:36 AM in response to badseed76

    A. We need to disable SIP.

     

    1. Boot into Local Recovery (Command+R).

    2. Start Utilities -> Terminal.

    3. Type csrutil disable in Terminal and press Enter/Return.

    4. Type csrutil status.

    5. Boot normally, and type csrutil status to confirm that all individual entries are still disabled.

     

    B. Update MBR to make NTFS bootable. Please ignore the i386 MBR error message, but not any others.

     

    sudo fdisk -e /dev/disk0

    p

    setpid 4

    07

    flag 4

    p

    w

    y

     

    Reboot and Test.

  • by badseed76,

    badseed76 badseed76 Feb 21, 2016 8:24 AM in response to Loner T
    Level 1 (10 points)
    Feb 21, 2016 8:24 AM in response to Loner T

    Hmmmmm, there seems to be a small wrinkle for me. Holding down CMD and R at startup dumps me into Internet Recovery, not Local. Double checked my drive and there's definitely a Recovery partition on here, so something seems to be amiss.

     

    For what its worth, in Internet Recovery mode Terminal insists that csrutil is not a known command.

     

    I can see/select Recovery HD when I hold option down at boot. For the purposes of shutting off SIP using the steps above, would booting into Recovery holding option at startup work?

  • by Loner T,

    Loner T Loner T Feb 21, 2016 8:39 AM in response to badseed76
    Level 7 (24,202 points)
    Safari
    Feb 21, 2016 8:39 AM in response to badseed76

    Command+Opt+R - Internet Recovery does not have csrutil. Command+R - Local Recovery has the command. If you end up in Internet Recovery, it usually indicates the Local Recovery being corrupt.

  • by badseed76,

    badseed76 badseed76 Feb 21, 2016 9:31 AM in response to Loner T
    Level 1 (10 points)
    Feb 21, 2016 9:31 AM in response to Loner T

    That's pretty much what I assumed was going on. Disk Utility insists the Recovery is OK, but that's obviously not the case. Looks like its time to figure this problem out and then back on to getting the Bootcamp issue squared away.

     

    BTW, thanks for all your help so far. Its great to not only get actual answers to my questions, but a step-by-step how-to as well as an explanation of things that gives me a better understanding of exactly what is going on "under the hood" (which is always good to have.)

     

    Thanks.

  • by Loner T,

    Loner T Loner T Feb 21, 2016 10:09 AM in response to badseed76
    Level 7 (24,202 points)
    Safari
    Feb 21, 2016 10:09 AM in response to badseed76

    There are a couple of ways to fix it.

     

    1. You can use How to install OS X on an external drive connected to your Mac - Apple Support and Internet Recovery to install the version of OS X shipped with your Mac and upgrade to the current version to match what you have on the internal disk.

    2. You can install the version that matches your internal disk version by (re)downloading the installer directly and installing it on a separate external disk or on the internal disk and apply Software Updates from App Store to match the current version on the internal disk.

    3. If you have a second Mac and appropriate cables/adapters, you can also use OS X El Capitan: Transfer files between two computers using target disk mode to get Windows up first or repair the Local Recovery, as you choose.

    4. If you use Time Machine and an external disk as your backup device and have a current backup, you can restore it, but you must ensure not to erase the internal disk, but just the Mac OS X partition, and not resize any partitions.

     

    There are many variants of such methods, but my recommendation is method 2 on an external disk.

  • by badseed76,

    badseed76 badseed76 Feb 22, 2016 4:15 AM in response to Loner T
    Level 1 (10 points)
    Feb 22, 2016 4:15 AM in response to Loner T

    Loner,

     

    Finally had a chance to "reinstall" El Capitan last night. After doing so, your steps listed above worked flawlessly (and on the first try!) to get my Boot Camp partition back up and running! Many many thanks for your patience and walked me through the process step by step (and, again, the lesson in exactly what is going on at the system level in terms of allocating the drives/partitions—always exciting to gain a better understanding of ho things actually work.)

     

    Thanks again!

  • by Loner T,

    Loner T Loner T Feb 22, 2016 6:04 AM in response to badseed76
    Level 7 (24,202 points)
    Safari
    Feb 22, 2016 6:04 AM in response to badseed76

    Glad to see it working. Please back up OS X, Windows and create a Windows System Restore point for future recovery.