Sierra on external SSD and High Sierra on internal SSD

Discussion in 'macOS' started by NutFlush920, Apr 3, 2018.

  1. NutFlush920 macrumors regular

    Aug 31, 2011
    I have 1 app that I use that isn’t compatible with High Sierra preventing me from upgrading. I have a Samsung T5 external SSD which I have partitioned to run Windows 10 boot camp. Can I create another partition on that external SSD and install Sierra on it for when I need to use that one app then install High Sierra on my internal SSD? Kinda like having a triple boot system covering all my bases until that app is compatible.
  2. Fishrrman macrumors P6


    Feb 20, 2009
    You can boot and run Low Sierra -easily- from an external drive.
    The Mac doesn't care WHERE you boot from.
    It DOES care that the copy of the OS is bootable.

    Does the external drive you want to use already have a Mac partition on it?
    If the answer is "no", I'm wondering if you could have problems trying to get it to work...

    Your best bet would be to start off with a "fresh, empty" drive formatted to Mac OS extended with journaling enabled.
    Get the copy of Low Sierra installed onto it, along with a recovery partition.
    THEN, put a partition for Windows onto the drive...

    You might even consider a small (120gb?) additional SSD for this purpose.
  3. poorcody macrumors 6502a


    Jul 23, 2013
    You can have multiple bootable partitions on an external drive. Don't know if Boot Camp partition complicates matter. I assume if Disk Utility lets you create a Mac partition on the existing drive, you should be okay.

    If you haven't considered it, an alternative would be to install Paralles or Fusion and run Sierra in a Virtual Machine on your existing drive. Developers do this regularly for software testing, and it works well. Then no rebooting, and you can actually run your "old" and "new" software simultaneously.
  4. NutFlush920 thread starter macrumors regular

    Aug 31, 2011
    Ive already got Windows 10 installed on a 120gb partition on the external SSD. The rest of the drive (370.91gb) is empty but formatted Mac OS Extended (Journaled).

    I don’t want to do a VM for the fact that they pretty much force regular purchased updates whenever there is a new version of OS X. I considered Virtual Box but not sure my app (TunesKit) works in VM’s.
  5. KALLT macrumors 601

    Sep 23, 2008
    You can just install it on that empty partition. The macOS installer creates additional partitions for you, which shouldn’t be a problem as long as you are using the GPT partitioning scheme.
  6. NutFlush920 thread starter macrumors regular

    Aug 31, 2011
    Is there a reason someone would pay to use VMWare Fusion or Parallels over the free Virtal Box solution to virtal machines?
  7. KALLT macrumors 601

    Sep 23, 2008
    The same reason someone would choose a Mac over a Linux computer: more reliable, looks and works better. I found VirtualBox decent performance-wise, but not that great. Plus their Mac host support is missing some features.
  8. poorcody macrumors 6502a


    Jul 23, 2013
    +1 on this. Also, I pay basically $20/yr for Parallels... they release a paid upgrade every year, but they always support two OS releases back, so I buy every other year... and there is always a $39 upgrade special that pops up every few months. I personally feel it is actually quite cheap for what you get.
  9. NutFlush920 thread starter macrumors regular

    Aug 31, 2011
    So I found out that TunesKit only works in Windows VM’s. The maker says iTunes can’t play video in Mac VM’s. Because of this I may as well just use Boot Camp for free and Sierra on my external drive and just boot into whichever OS I need at the time. I’ll run High Sierra on my internal SSD as my primary OS.

    Thanks all.
    --- Post Merged, Apr 5, 2018 ---
    If I did do VM do y’all suggest Fusion or Parallels

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