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MP 1,1-5,1 Booting back to MacOS from Windows - issue

S

stockholm80

macrumors member
Original poster
Jul 12, 2013
65
14
Los Angeles
I have Mac Pro 5,1 running Windows 10 (in legacy mode) on a OWC SSD and two installations of MacOS Mojave 10.14.6 on two other separate hard drives. One is a Crucial MX300 SSD that I use as my main MacOS Drive. The other is a Seagate 4tb mechanical drive with a clone of my OS. Both drives are formatted HFS+. I converted them from APFS with the help of Carbon Copy Cloner. I have BootCamp 5.1.5621 installed in Windows.

For some reason Windows will only allow me to boot back to Mac OS on the mechanical drive and not the SSD. If I select the SSD and reboot I just come back to Windows again.

Does anyone have an idea why this is happening? It’s a major annoyance for me since I need to boot back to my slow drive and then go through the startup disk selector to get to my main OS on the SSD. Any help would be appreciated!
 
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I have read that thread thoroughly but I’m not finding anything about my specific issue in there.

I have no problem with my Windows 10 install and it’s been running fine for almost a year. I’m not using the APFS file system on any of my MacOS installs so I don’t see the necessity to update to BootCamp 6,1. BootCamp is seeing the drives just fine.

My specific issue is that I can only restart into MacOS on one of my drives. I’m wondering why my system lets me boot to my mechanical drive but not my SSD. The are both sitting in the internal SATA bays (and are identical clones of the same system) so why is it just working on just one of them?
 
stockholm80 said:
1. The other is a Seagate 4tb mechanical drive with a clone of my OS. Both drives are formatted HFS+. I converted them from APFS with the help of Carbon Copy Cloner. I have BootCamp 5.1.5621 installed in Windows.

2. For some reason Windows will only allow me to boot back to Mac OS on the mechanical drive and not the SSD. If I select the SSD and reboot I just come back to Windows again.
Click to expand...

1. I don't think APFS is really for large spinning hdd. Maybe why macOS didn't auto-convert.

2. Yeah, some like that fancy way.
Personally, I just set one to be the default OS boot. If I ever need to get to the other, I just:
- Shut-Down
- Turn back On. Press key to select alternate OS/boot-drive.
- Use Windows. Shut-Down Windows.
- Reboot and macOS should auto-boot like always.
 
I installed the latest BootCamp drivers for iMacPro today in Windows, and I even converted my main OS SSD to APFS, but it had no effect. If I choose that drive in the boot selector Windows just restarts back into Windows again. Seems like it's only able to set the older hard drive to boot back into MacOS no matter what I do. I wonder if it's some kind of incompatibility with the Crucial SSD...

I was hoping to add some Thunderbolt 3 devices to my setup but right now this gives me a total of 6 min boot time from cold boot which makes it too cumbersome. Any ideas would be appreciated how to solve this!
 
It happens to me sometimes after Windows updates. I usually do an NVRAM/SMC reset and it all goes back to normal on my MP51. I've had to do that a few times.
 
Ok, good to hear that it can happen to someone else too. I'll try an SMC and NVRAM reset and see if it helps. Which Windows 10 version are you using right now?
 
I got sorted out. I did a clean install of the latest Mojave with a usb installer and Windows is now able to boot back into MacOS (formatted as APFS) without issues.

Maybe there is some slight difference when you try to boot back to MacOS to a drive that has been cloned with CCC instead of one that was installed by the MacOS installer. Not sure.
 
I don't have any trouble with CCC/Win Booting.

Pay particular attention to your CCC settings when cloning. These are my settings...

Screen Shot 2019-11-23 at 2.19.46 PM.png
 
Thanks for sharing your settings. I’ve been using those exact settings in CCC too. Maybe my previous MacOS installation got corrupted at one point due to an update or something. I hadn’t done a clean install since Sierra I think.
 
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Got this update to Boot Camp today.jpg


Got this update today. Might solve things. I haven't been able to try but I for along time had trouble with chaning the Startup Disk from within Windows – it seems the computer would only listen to what was set in the Startup Disk control panel in MacOS. Hopefully that isn't the case anymore.

Edit:
And of course it didn't work. For me the computer only cares about what I do in the MacOS control panel when it comes to this.
 
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