MBP 2016 can't boot from external SSD

Discussion in 'MacBook Pro' started by dealy663, Jun 1, 2017.

  1. dealy663 macrumors newbie

    dealy663

    Joined:
    Jun 1, 2017
    #1
    Hi I have a new MacBook Pro 13" with a touch bar and 4 USB type-c ports.

    I also have an external Samsung T3 SSD which I wish to boot from. I've installed Windows 10 on this SSD, but can't get the bootcamp drivers installed without booting from it on the MBP.

    When I reboot holding the Option key the MBP does not show the external SSD as a choice for booting. However if I take the same SSD and plug it in to my 2012 MBP retina the older notebook is able to boot from that drive with no problem.

    Does anyone have any suggestions on how to get this SSD to work on my new MBP?

    Thanks, Derek
     
  2. Samuelsan2001 macrumors 604

    Joined:
    Oct 24, 2013
    #2
    As far as I know you have to set it up using bootcamp as you create the drive.
     
  3. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #3
    Within the Bootcamp Assistant, click on the Action menu and then select download Windows Support Software
     
  4. MichaelDT, Jun 3, 2017
    Last edited: Jun 3, 2017

    MichaelDT macrumors member

    Joined:
    Aug 18, 2012
    #4
    2016 MBP only supports booting from a GPT/GUID partition map for Windows 10 UEFI booting on a USB drive, from what I can tell. The old way makes a MBR style partition this won't work on the 2016 but does work on older MacBook Pros. If you have a Windows 10 PC available follow this guide http://blog.exchange-addict.com/2013/02/windows-to-go-uefi-only_19.html you don't need to do any of the stuff with the xml files onward.

    This will give you a Windows 10 Install. You will also need an external keyboard and mouse for first boot. After first boot you'll need all the boot camp support software downloaded in macOS per above post on a thumb drive or some other device. Run the setup.exe in the bootcamp folder that and then the internal keyboard will start working and you should be good to go.

    I should mention, Windows on a USB drive won't let you upgrade to the latest creators update without using the USB in a virtual machine. So, if you don't have the latest creators .iso and you want to be on the latest verion, you can download it here https://www.microsoft.com/en-us/software-download/windows10ISO

    Also, you probably will want bitlocker encryption if you travel with this drive. This guide https://www.howtogeek.com/howto/6229/how-to-use-bitlocker-on-drives-without-tpm/ explains how to do this graphically. This method is machine agnostic, thus you can use it in any machine you like.
     
  5. Boneheadxan macrumors regular

    Boneheadxan

    Joined:
    Jul 19, 2009
    #5
    I'm using a T3 to run Windows 10 for my gaming partition. It boots perfectly fine on a MBP 2016. I had a bit of trouble during the installation stages, but I remember using a Windows program called Rufus to complete the installation.
     
  6. dealy663 thread starter macrumors newbie

    dealy663

    Joined:
    Jun 1, 2017
    #6
    Cool, thanks for the info on the GPT vs MBR stuff. Hopefully I can get the drive converted.

    l
    --- Post Merged, Jun 5, 2017 ---
    Well that's good to hear that it is technically possible to make this work. Can you point to a set of instructions you followed? How did you get the MBP to recoginze that the T3 had a bootable partition?
     
  7. dealy663 thread starter macrumors newbie

    dealy663

    Joined:
    Jun 1, 2017
    #7
    So far I have not been able to figure out a way to make a bootable GPT partition on the T3 SSD.

    So I first tried creating a GPT boot sector before formatting. However the Win 10 installer wouldn't install on a GPT disk.

    Next I went back to MBR and got Win10 installed with the hopes that I'd later be able to go into dispart.exe and run Convert GPT.

    If I try to run bcdboot from a Win7 Virtual Machine it errors out, something about bcryptdll not being a windows program.

    But I am stuck unable to get the bootable files installed on my first partition.

    Any other suggestions?
     
  8. MichaelDT macrumors member

    Joined:
    Aug 18, 2012
    #8
    If you use a vm, you need to boot it in UEFI mode with the GPT formatted drive. I believe by default most vms still use BIOS with MBR. Usually there is a setting you need to enable for experimental UEFI.

    Be warned though, using the vm method instead of WinToGo method every time you change hardware windows 10 will need to be reactivated. I.e. when you go from vm to hardware you will need to reactivate. If you do this enough Windows will refuse to activate until you call Microsoft, which is annoying.
     
  9. Boneheadxan macrumors regular

    Boneheadxan

    Joined:
    Jul 19, 2009
    #9
    https://rufus.akeo.ie - This is what I used to create the partition and install Windows10.

    A few other methods I tried always got stuck on the boot screen. With Rufus I remember it being fairly straightforward, only issue being, you would need a Windows computer to run the program.

    I can currently boot the T3 from any of my Macs and has been working really well for gaming! Hope you sort this out.
     
  10. DRDR macrumors member

    Joined:
    Jul 23, 2008
    #10
    Try to unstall reFind. It's an EFI bootloader which might be able to boot in legacy mode.
     
  11. dealy663 thread starter macrumors newbie

    dealy663

    Joined:
    Jun 1, 2017
    #11
    I had tried Rufus last week and it stopped in the middle with an error. I was running it from within Windows guest on VMWare Fusion. I'm wondering if it failed because I was running on a VM instead of natively in Windows
     
  12. PIX macrumors member

    Joined:
    Feb 19, 2008
    #12
    On the subject of booting from an external drive has anyone successfully boot a 2017 MacBook Pro using an external hard drive? I'm running MacOS 10.12.5 on the external drive that will boot fine on a 2016 MacBook Pro. I use the external drive to boot from so I can restore (15 mins) to a custom image build for our company Macs. When booting to the Mac from the same external it won't boot (circle with the diagonal line) on the latest MacBook Pro. For now I plan to setup each new Mac from scratch which will take about 1.5 hours with all the software installs.

    Suggestions appreciated?
     
  13. dealy663 thread starter macrumors newbie

    dealy663

    Joined:
    Jun 1, 2017
    #13
    I was never able to get this to work. Just like you the external SSD would boot when plugged into my 2012 retina MBP. Apple really gets on my nerves by doing stuff like this. They make their systems harder to use, more expensive, fewer connection options and practically impossible to upgrade or repair. Its really disappointing.
     
  14. jzuena, Jul 5, 2017
    Last edited: Jul 5, 2017

    jzuena macrumors 6502a

    jzuena

    Joined:
    Feb 21, 2007
    Location:
    Lexington, MA, USA
    #14
    I just went through several installation attempts to put Windows 10 on an external USB3 drive on my new 2017 iMac, and when I was about to give up and get a Thunderbolt 3 SSD, finally succeeded. At first I thought I'd help things along and format the target drive MBR, but that ends up making things worse, since Windows 10 doesn't really like MBR formatted disks. I ended up going with the VirtualBox method with a couple of twists:
    1. Format the drive GUID with a single ExFAT partition. This actually creates two partitions: a small EFI boot partition and the ExFAT partition. The ExFAT partition gets deleted and replaced with NTFS by the Windows installer, but I thought it best to have something that Windows will recognize so I didn't make it MacOS Extended.
    2. Ensure a hybrid MBR is not used as described in this link. (it was, so I fixed it)
    3. Install via VirtualBox as in this link. This got me really close, but the Windows installation wasn't showing up when holding down the Option key at boot (similar to you). Then I realized that I had to enable EFI in the Virtual Machine (like MichaelDT says above) so that Windows would know how to write to the EFI disk. Before that, I was having the Windows installer delete all partitions on the drive in order to allow Windows to partition it, which was destroying the EFI partition. Once EFI was enabled, I could delete just the ExFAT partition and and have Windows partition the rest of the drive. Then I got the "EFI Boot" option in my boot drive list. Selecting EFI Boot got to the Windows 10 partition and it finished the install. I did use Anniversary Update rather than Creators Update, since both the Microsoft and Apple sites said there was a bug installing Creators Update in Bootcamp. I got an error updating to Creators, but I haven't added a license key and activated yet. I also had issues installing the Bootcamp drivers from the single setup application, and installed each of the drivers individually.
    4. At my next macOS boot, re-ensure a hybrid MBR isn't configured as in step #2 (it wasn't).
    This seems to be working so far, and was simpler than some of the other methods. I just have to order a Win10 Home license from Amazon before my 30-day evaluation is up, and Upgrade my VMware Fusion 7 to 8.5 in order to set up Windows 10 to both boot native and as a VM.
     
  15. eonaeon macrumors member

    Joined:
    Feb 15, 2008
    Location:
    Down Under
    #15
    Thanks very much for this, I followed some other instructions but my iMac wouldn't detect the new install... I followed your instructions, and there were a couple of head scratching moments, but otherwise worked my way through and it works fine.

    Interestingly enough - I was using the Creator's update and it worked fine!
     
  16. jzuena macrumors 6502a

    jzuena

    Joined:
    Feb 21, 2007
    Location:
    Lexington, MA, USA
    #16
    I guess the bug in Creators update is specific to something in Boot Camp Assistant that a clean install doesn't trigger. I ended up hosing my install when I set up Fusion to also run a VM on the raw NTFS partition. I gave in and created a 50GB partition on my internal SSD and have Windows mount the external USB3 drive as a D: drive. Now it works native and under Fusion, although I have to mount the drive as USB2 under Fusion. I was able to enter my Windows 7 license to activate Windows 10, so I am set. If I leave the VM running too long (like all night or all day while at work) it deactivates, but if I then leave Windows running native for a day while at work it reactivates. Annoying, but good enough for occasional use.
     

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