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Mojave blew away my windows partition

maflynn

maflynn

macrumors Haswell
Original poster
May 3, 2009
74,300
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So it seems Mojave messed up my Windows partition on my iMac.
my setup is different then a typical bootcamp set up. I run windows on the internal SSD of my iMac. I split up the Fusion drive and installed windows on that. macOS is being run on a Samsung T3 USB drive.

Whenever I wanted to boot into windows, I'd reboot with the option key down, select the windows drive and viola.

I see the partition in Disk utility so the drive is there
diskutility.png


The data is still there, as I see it in Finder
win10.jpg


Its not bootable any longer. For instance I shut down my iMac, and unplug the T3. On powerup, I get the question mark folder. I beleive I was running in windows for DP1, but now with DP2 its no longer bootable.

I thought it was safe because macos is running competely on the external SSD.

I'm not sure what I can do to get it back to being bootable. :(
 
maflynn said:
So it seems Mojave messed up my Windows partition on my iMac.
my setup is different then a typical bootcamp set up. I run windows on the internal SSD of my iMac. I split up the Fusion drive and installed windows on that. macOS is being run on a Samsung T3 USB drive.

Whenever I wanted to boot into windows, I'd reboot with the option key down, select the windows drive and viola.

I see the partition in Disk utility so the drive is there
View attachment 767475

The data is still there, as I see it in Finder
View attachment 767479

Its not bootable any longer. For instance I shut down my iMac, and unplug the T3. On powerup, I get the question mark folder. I beleive I was running in windows for DP1, but now with DP2 its no longer bootable.

I thought it was safe because macos is running competely on the external SSD.

I'm not sure what I can do to get it back to being bootable. :(
Click to expand...
Maybe it's not feasable for you but, if I were you, after backing up the internal Windows just for safety reasons, I would partition that drive so that a small part of it runs a Mac OS. The rest would remain Windows as it is now.
I would be curious to see what happens in such a configuration when one boots with the option key...
If you have a back up of your windows it seems to me you would not risk losing data... and what is there to lose by trying it?

By the way since you have a lot of knowledge I unfortunately lack, have you any idea why after re-installing Bootcamp Win 10 in a part of the inner drive of my MP End 2013, the option key start up gives me two (2) Bootcamp entries although there is of course only one Bootcamp Win 10 sharing the inner drive with Sierra?
It is not tragic but I would like to get rid of the "second" Bootcamp option if this is possible...
Hoping you solve your problem (and maybe help me to solve mine...):)
 
Same issue I just went into Preferences and Startup Disk and chose windows. It works fine.

Now I press Option when booting up for Mac.
 
powerocool said:
Same issue I just went into Preferences and Startup Disk and chose windows. It works fine.

Now I press Option when booting up for Mac.
Click to expand...

It's a known issue, I posted something similar, very much related in https://forums.macrumors.com/thread...he-firmware-on-my-imac.2124330/#post-26181406, someone in that thread mentioned something about repairing it with Disk Utility but after trying many times it was not fixed. I believe the bug was introduced in the Mac's firmware and not necessarily on the disk's partition, since your SSD is external and should not be affected. I also have an external SSD that can't be used to boot from anymore.

I believe the only way to fix this is to make sure Apple knows of this, and fixes this in future betas / final release.
 
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jdasikainen said:
try using windows usb and repairing the bootloader
Click to expand...
Yeah, I think that's my only option at this point

Riwam said:
after backing up the internal Windows just for safety reasons, I would partition that drive so that a small part of it runs a Mac OS. The rest would remain Windows as it is now.
Click to expand...
I have a macOS partition, its an external SSD. Because I'm using the small SSD that is built into the iMAc (My fusion drive is 120GB SSD + 2 TB spinning drive), there is no room to hold both.

powerocool said:
Same issue I just went into Preferences and Startup Disk and chose windows. It works fine.
Click to expand...
I don't think its the same issue, because the internal drive is all windows and I'm running off an external drive, the startup disk selection never worked for me, that's why I always had to use the option key on bootup. I'm not sure why, and it wasn't a huge issue so more or less ignored that problem.
 
The USB I made is not bootable on my iMac but it is on my other windows machine, so to me that points something that Mojave has changed that broke Windows. My Windows partition may be bootable, but with some change to firmware or something its not working
 
What follows is my speculation and opinion only.

I'm wondering if at some point in the future -- particularly if Apple starts using its own CPU design -- "Windows support" on the Mac will be dropped entirely.

That is... no more "BootCamp on the Mac", no more native Windows booting.

It may still remain possible to run Windows via emulation (as it can be done now), but the time may be coming where Apple no longer endorses or permits Windows booting on Macs.

Again, my speculation only.
 
Last edited:
Fishrrman said:
That is... no more "BootCamp on the Mac", no more native Windows booting.
Click to expand...
I will say that thought ran through my head. I've always had small issues with windows on a Mac, but nothing major. I have a windows laptop that I'm putting through its paces to determine if I want to keep it. this issue so far has pushed the needle of keep vs return closer to the keep side
 
I had this same issue with my Mac Pro. Windows 10 was working fine by using BootChamp to reboot in High Sierra. As soon as I tried Mojave I was no longer able to access Windows at all. I went back to High Sierra and it seems to have fixed my issues.
 
AaronE said:
I went back to High Sierra and it seems to have fixed my issues.
Click to expand...
How did you do that?

I booted up my High Sierra external drive and the result was the same :(

Maybe I need to fully "down grade" or wait for DP3 and hope for the issue to be resolved. Tbh, I hope it is a bug and not a feature that apple is removing
 
Ricktracer said:
It's a known issue, I posted something similar, very much related in https://forums.macrumors.com/thread...he-firmware-on-my-imac.2124330/#post-26181406, someone in that thread mentioned something about repairing it with Disk Utility but after trying many times it was not fixed. I believe the bug was introduced in the Mac's firmware and not necessarily on the disk's partition, since your SSD is external and should not be affected. I also have an external SSD that can't be used to boot from anymore.

I believe the only way to fix this is to make sure Apple knows of this, and fixes this in future betas / final release.
Click to expand...


I had something similar too and first aid didn't fix it. I found a youtube video (prior to mojave) that suggested I unencrypt my drive, that the Master boot record/partition table is kept on the encrypted drive and first aid can't see it in recovery mode.

Bottom line I did unencrypt and then ran first aid in recovery mode and it fixed my issue.
 
TheAppleFairy said:
Bottom line I did unencrypt and then ran first aid in recovery mode and it fixed my issue.
Click to expand...
Interesting, in my case however my internal SSD is completely windows. I'll have to boot up my iMac and see if there's a hidden partition on the internal SSD
 
maflynn said:
Interesting, in my case however my internal SSD is completely windows. I'll have to boot up my iMac and see if there's a hidden partition on the internal SSD
Click to expand...

Where is the bootloader located? I understand the partition is on a separate drive, but the instructions for booting it may be located (or at least appear to be, if it fixes the issue) on the internal drive.
 
TheAppleFairy said:
Where is the bootloader located? I understand the partition is on a separate drive, but the instructions for booting it may be located (or at least appear to be, if it fixes the issue) on the internal drive.
Click to expand...
I have to look, I thought it was completely on the external SSD.
 
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Well I have one dead iMac at this point. I went to unencrypt my drive, which well swimingly, but then things went south. No apps worked, I rebooted and while I could log in, no apps were starting, not even the Finder.

I'm going to wipe the computer and reinstall High Sierra :(

I know, I know, its a beta and these things happen. I have a High Sierra image on another external drive, but I might take this opportunity to wipe it and start over.
 
maflynn said:
Well I have one dead iMac at this point. I went to unencrypt my drive, which well swimingly, but then things went south. No apps worked, I rebooted and while I could log in, no apps were starting, not even the Finder.

I'm going to wipe the computer and reinstall High Sierra :(

I know, I know, its a beta and these things happen. I have a High Sierra image on another external drive, but I might take this opportunity to wipe it and start over.
Click to expand...



well....that's not good. hope they get this resolved.
 
TheAppleFairy said:
well....that's not good. hope they get this resolved.
Click to expand...
Yeah, but I suppose its a blessing in disguise. I think I may re-fuse my internal drive and reinstall macOS (High Sierra) on it. I was a bit underwhelmed and disappointed with Mojave. Again I understand its a beta and I probably jumped on it too soon. I was submitting a fair amount of bug reports, but it made my Mac a bit of a pain to use, i.e., safari losing my login credentials to all my sites and I had to continually log in.

Since I lost my windows drive as well (nothing that I couldn't get back) and I have a windows machine I really don't need to run macOS on an external drive. I've largely been disappointed with the performance of AFPS, I might as well setup Fusion again and bring my iMac back to stock configuration
 
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same issue
bootcamp is practically non existent
have tried repairing and doing everything, short of downgrading to high Sierra
had high hopes from DB3 of solving this issue but it didn't do anything
 
Hellsurfer said:
same issue
bootcamp is practically non existent
have tried repairing and doing everything, short of downgrading to high Sierra
had high hopes from DB3 of solving this issue but it didn't do anything
Click to expand...

maflynn said:
Yeah, but I suppose its a blessing in disguise. I think I may re-fuse my internal drive and reinstall macOS (High Sierra) on it. I was a bit underwhelmed and disappointed with Mojave. Again I understand its a beta and I probably jumped on it too soon. I was submitting a fair amount of bug reports, but it made my Mac a bit of a pain to use, i.e., safari losing my login credentials to all my sites and I had to continually log in.

Since I lost my windows drive as well (nothing that I couldn't get back) and I have a windows machine I really don't need to run macOS on an external drive. I've largely been disappointed with the performance of AFPS, I might as well setup Fusion again and bring my iMac back to stock configuration
Click to expand...


Well what I did to fix it in DB2 has broke in DB3, so I can no longer bootcamp again. I tried the same steps to fix my bootcamp and doesn't work.

I assume everyone is getting the same thing. I hold in option when booting and select the windows partition, but it goes directly into MacOS.
 
Never partition a Fusion Drive. You'll end with a partition which is very slow due the 5400 rpm hard drive speed.
 
So I found the answer to the boot camp issue here. Once I did that one time I can go back and forth without an issue.

LINKED URL said:
A workaround I have discovered is to go to System Preferences -> Startup Disk, and select the OS that you cannot now access from the boot screen as your default startup OS (in my case Boot Camp Windows 10). Then at the boot screen you can access Mojave as normal when you want to. It is not really a fix but an easy workaround until the fix comes out. It worked for me at least.
Click to expand...
 
So are we screwed until hopefully the next beta? Not having my Windows partition is killing me. Major No Man’s Sky update, GTA Online update, etc.
 
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