Which Bootable External SSD?

Discussion in 'MacBook Pro' started by superficial, Oct 22, 2018.

  1. superficial, Oct 22, 2018
    Last edited: Oct 22, 2018

    superficial macrumors newbie

    Oct 22, 2018
    My new MBP is driving me crazy! I am tearing my hair out trying to install Windows on an external drive and I've basically come to the conclusion that it's not possible with the hardware I've got. I need to do some work on Windows but I don't really want my limited SSD space being taken up by Windows in the long run.

    I've tried loads of methods - and the crux of it that the damn machine won't boot from my external SSD. I have tried with various techniques of shoehorning Windows onto an external drive HERE, HERE, and HERE. I've tried VMWare Fusion (free 1 month trial) with Rufus and WinToUSB. I've also tried this method using VirtualBox.

    I then decided that perhaps it's Windows. So I tried a Linux Ubuntu disk image. That didn't work. Unfortunately I don't have another external drive I can use to try this on.

    It's a 2018 Macbook Pro 13" Touchbar base model (8Gb Core I5 with 256Gb SSD). The external drive I'm using is a Crucial M4 256Gb SSD with a Sabrent SATA to USB-C adaptor (The latter was chosen because it's supposedly reliable for using with external SSD boot drives).

    A couple of other points:
    • I'm aware that there is some security setting in Mojave that doesn't allow you to boot from USB without changing some settings (it's been a while and I forget exactly what this was, but it's been disabled).
    • I'm also aware there is an issue with Hybrid MBRs causing a problem. I've checked and I don't have a hybrid MBR (HERE)
    Edit to add: (Forgot to describe the issue)
    The ISO etc will appear to have copied properly, and it all looks good. I can select restart from the external ssd in system preferences (no error message at this stage), or alternatively I can boot holding down option for the boot menu. This works and displays my internal storage as well as "EFI Boot" which I think is correct. I know some people report a red cross through this icon, but that's not the case for me. However, if I click on it, the system restarts and boots with an Apple logo (no Windows logo) into Recovery mode. No error message (at least none that I can see).

    • Question 1) Am I being stupid, is there anything I haven't tried?
    • Question 2) Assuming I'm not being stupid and it's a hardware issue, what external SSD drive should I buy in order to get all this to work? I have seen a forum post saying that they had issues until they bought a Samsung T3 which worked fine. Those seem to have been superseded by the T5 so should I assume they will work? I would gladly pay the £80 for a drive if I knew it would work, but at this point I am somewhat skeptical and don't want to throw away money on this.
    • Question 3) I know some people suggest using CC Cloner. Is this the REAL answer to my problem?
  2. Mike Boreham, Oct 22, 2018
    Last edited: Oct 22, 2018

    Mike Boreham macrumors 68000

    Aug 10, 2006
    The T2 chip on 2018 Macs requires permission to boot from externals but no idea how that affects Bootcamp.

    I successfully run Bootcamp from a Samsung T3 in this thread, but that was not a 2018 T2 chip Mac. As you can see I actually started with a working Bootcamp partition internally which I migrated to the external with Winclone. It involved a registry edit before the migration.

    After using both Parallels and Bootcamp at various times I have settled on Parallels as a whole lot less trouble. The Parallels VM file is highly portable and easily backed up. I frequently have the Parallels VM on an external drive with no problem to set up or use. I would be surprised if the T2 chip prevented having the Parallels VM on an external (but I could be wrong about this!)

    EDIT Carbon Copy Cloner won't clone a Bootcamp partition. It will clone a Parallels VM file of course.

    EDIT 2 Samsung T5 should work fine, I have both T3s and T5s.

    EDIT 3 I have never used VMware but would be surprised if everything I have said about Parallels isn't equally true about VMware.
  3. solouki, Oct 22, 2018
    Last edited: Oct 23, 2018

    solouki macrumors member


    Jan 5, 2017
    VirtualBox VMs...

    On a 2018 MBP running Mojave I am running VirtualBox VMs for Ubuntu 18.04 LTS, Windows 10 Pro with their "vdi"s all stored on an external Samsung T5 SSD. I don't use Bootcamp, so I can't speak to booting off of the T5, but if you can run Windows as a VM then I know that this works.

    Good luck!
  4. superficial thread starter macrumors newbie

    Oct 22, 2018
    Thanks for the replies.

    Solouki I think I am going to just go with your suggestion. I've managed to get Windows running on Virtual Box. I can cut my losses and I don't need to buy any more hardware (or software). Once I realised that I can just plug in the SSD whenever I need to run Windows but I don't need a massive VM file sitting around on my hard drive it's all good. Thanks for the suggestion.

    Having said that, VirtualBox is a bit laggy. It's workable but VMware is definitely smoother and a better experience. I'm not sure whether I just need to allocate more RAM or optimise my VM file somehow. I guess I didn't really solve the problem, but we found a workaround. Thanks again.
  5. solouki macrumors member


    Jan 5, 2017
    Superficial, glad you found a workaround. I'm sure VMware is better than VirtualBox, but you may find that if you allocate more memory than the VirtualBox defaults to the VM it will become "smoother". In addition, set the Video Memory to 128MB. Also, you might try playing around with the 2D/3D acceleration parameters to see if it improves the performance. Since you have 8GB on your MBP, you might try half, or even more, of it for your VM. I typically allocate 8GB of RAM for my Windows 10 Pro VM, but I have a 15" MBP so this is not a problem. Good luck, and let us know what ultimate solution works best.

    EDIT: Almost forgot, but I assume you probably already did this, but I thought I should mention it just in case you're new to VirtualBox: make sure you load the Guest Additions to VirtualBox.
  6. jlc1978 macrumors 68020


    Aug 14, 2009
    I just loaded VB on my 2018 15" MBP and while I can live with the laggy as all I run is Office on occasion when I need to ensure a file looks ok in Windows; V B is freezing whenever I open some applications, such as their movie player. Not so much an issue as I don't plan on using it but it does raise questions about VVB's reliability. I used Parallels for years but am tired of the yearly update nags..
  7. JimmyG1357 macrumors newbie

    Oct 30, 2018
    Ypsilanti, MI
    I was going through the same issue on my 2018 Mackbook Pro. I was able to get my system to boot Windows from the external HD by adjusting the Startup Security to No Security. I am not sure what the ramifications are to setting it like this, but it did the trick.
    I followed 9to5Mac's video on Youtube, but I'm fairly certain that most of the other methods would work as well. It was the Mac's system security that was the problem, not the Windows 10 installation method. Here is a link to the video process that I used;

    I determined it was an issue with the Mac and not the install process by creating a Mojave install disk, and having the same problem. I booted into Recovery mode to access the Startup Security application. (Command R) during boot.

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6 October 22, 2018