I found a way to solve my issue.
First, I have an old mid-2010 iMac. So the only way to get BOOTCAMP running is to use MBR mechanism. MBR can only address 4 partitions in 2.2Tb of disk space.
Notice that Windows 7 and 8 can only boot on MBR disks. Windows 10 can use MBR as well as GUID disks (EFI = GUID). But if you have a Windows 10 MBR Winclone backup, you can’t restore it on a GUID disk, as some boot files may be missing (I guess symmetrically GUID can’t be restored on MBR disk).
Second, I have a large hard disk 10Tb and I want to use all the size (otherwise I will loose 10Tb - 2.2Tb = 7.8Tb of space, sounds bad). So GUID partition scheme must be also set for this disk. Hopefully, there is a way to get both systems alive (MBR & GUID) and this trick was made by Apple as a “hybrid” MBR.
So my BOOTCAMP partition must be in the first 2.2Tb of HD and one of the 4 1st partitions (MBR limits).
The only way to do this, is to have BOOTCAMP in 1st place. In fact it’s gone be the 2nd, due to Apple’s small EFI mandatory partition made to access the full 10Tb of the disk (see next Terminal.app command):
# diskutil list
To get this Hybrid MBR/GUID disk, enter the following Terminal.app command:
# sudo diskutil partitionDisk disk1 2 GPTFormat “MS-DOS FAT32” “BOOTCAMP” 96Gb JHFS+ “tanker10Tb” R
*** Warning ***
Above command will erase the whole content of your hard disk (no return back) and create 2 partitions. Be careful to give the right disk number shown by diskutil list command. Mine was disk1. But it can differ depending on your disks configuration.
- BOOTCAMP will be the 1st partition defined as FAT32 and sized 96Gb.
- tanker10Tb will be the 2nd one defined as a Journalised HFS+ that takes the rest [R] of the disk.
Then I restored my Winclone backup to BOOTCAMP partition.
But one more thing have to set in order to get Windows running. BOOTCAMP partition has to be “ACTIVE”. This is made using Windows Tools USB key (download here).
Reboot your computer and press [ALT] key to choose Windows Tools USB key (named EFI boot).
On 1st screen, choose [Next]:
2nd screen, choose “Troubleshoot” option:
And launch “Command Prompt”:
A window opens where you can enter DOS command
[X:\>] (sorry, french version):
Enter following command:
List your volume:
> LIST VOLUME
Choose your BOOTCAMP partition:
> SELECT VOLUME 1
Make it active:
Verify that and asterisk is beside your BOOTCAMP partition and exit:
> LIST VOLUME
Shutdown and boot your computer holding [ALT] key in order to choose BOOTCAMP.
It should run smoothly!
Hope this tutorial will help other people.