after following this detailed guide I've stuck at point 5. which did not make my external 5TB HDD to boot, no "Install Windows" nor "Windows" shows in boot selection menu:
bless --folder /Volumes/WINSTALL/efi/boot --label "Install Windows"
mkdir /Volumes/WINSTALL/label
bless --folder /Volumes/WINSTALL/label --label "Windows"
Current disk configuration of iMac 2012:
- 1TB internal HDD (currently installed Catalina, Windows 10)
- 240GB external SSD (Thunderbolt 2: currently installed Mojave, High Sierra)
- 5TB external HDD (USB: empty)
Target is to install Windows 10 on external Thunderbold2 240GB SSD along with the other OS installations.
diskutil list
shows following configuration:
/dev/disk0 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *240.1 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_APFS Container disk4 117.0 GB disk0s2
3: Microsoft Basic Data BOOTCAMP 87.7 GB disk0s3
4: Apple_Boot Boot OS X 134.2 MB disk0s4
5: Apple_APFS Container disk2 35.0 GB disk0s5
/dev/disk1 (internal, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *1.0 TB disk1
1: EFI EFI 209.7 MB disk1s1
2: Apple_APFS Container disk3 395.0 GB disk1s2
3: Microsoft Basic Data BOOTCAMP 605.0 GB disk1s3
/dev/disk2 (synthesized):
#: TYPE NAME SIZE IDENTIFIER
0: APFS Container Scheme - +35.0 GB disk2
Physical Store disk0s5
1: APFS Volume macOS-HS 14.2 GB disk2s1
2: APFS Volume Preboot 22.8 MB disk2s2
3: APFS Volume Recovery 512.1 MB disk2s3
4: APFS Volume VM 2.1 GB disk2s4
/dev/disk3 (synthesized):
#: TYPE NAME SIZE IDENTIFIER
0: APFS Container Scheme - +395.0 GB disk3
Physical Store disk1s2
1: APFS Volume Macintosh HD - Data 367.9 GB disk3s1
2: APFS Volume Preboot 25.6 MB disk3s2
3: APFS Volume Recovery 525.8 MB disk3s3
4: APFS Volume VM 8.6 GB disk3s4
5: APFS Volume Macintosh HD 11.3 GB disk3s5
/dev/disk4 (synthesized):
#: TYPE NAME SIZE IDENTIFIER
0: APFS Container Scheme - +117.0 GB disk4
Physical Store disk0s2
1: APFS Volume iMextMojave 85.3 GB disk4s1
2: APFS Volume Preboot 26.1 MB disk4s2
3: APFS Volume Recovery 507.5 MB disk4s3
4: APFS Volume VM 2.1 GB disk4s4
/dev/disk5 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *5.0 TB disk5
1: EFI EFI 209.7 MB disk5s1
2: Apple_HFS seagate 5.0 TB disk5s2
3: Microsoft Basic Data Winstall 15.9 GB disk5s3
Because the first attempt with external 5TB HDD did not work I tried to use 240GB SSD with Bootcamp Assistant in Mojave (OS booted from that SSD) to create installation USB-stick and to create Bootcamp partition on SSD with ISO Win10 64-bit 1909 as recommended in the guide.
At point 8. I tried to assign letter "S" to EFI partition on SSD but it failed with message There is no volume specified. Please select a volume and try again. So I tried to mount the partition with command mountvol S: /S
without success and when I tried to run mountvol
with no arguments it did not even show EFI partitions from the other disks as an option.
Disk status in Windows Setup:
DISKPART> list disk
Disk ### Status Size Free Dyn Gpt
-------- ------------- ------- ------- --- ---
Disk0 Online 223 GB 0 B
Disk1 Online 931 GB 0 B
Disk2 Online 238 GB 0 B
DISKPART> select disk 0
Disk 0 is now the selected disk.
DISKPART> list partition
Partition ### Type Size Offset
------------- ---------------- ------- -------
Partition 1 Primary 200 MB 512 B
Partition 2 Primary 108 GB 200 MB
Partition 3 Primary 81 GB 109 GB
Partition 4 Primary 128 MB 190 GB
DISKPART> list volume
Volume ### Ltr Label Fs Type Size Status Info
---------- --- ----------- ----- ---------- ------- --------- --------
Volume 0 E BOOTCAMP FAT32 Partition 81 GB Healthy
Volume 1 C BOOTCAMP NTFS Partition 562 GB Healthy
Volume 2 F NTFS Partition 529 MB Healthy Hidden
Volume 3 D WinInstall exFAT Partition 238 GB Healthy
Edit: "list disk" output from existing Win10 Bootcamp installation on Internal HDD
DISKPART>
Disk ### Status Size Free Dyn Gpt
-------- ------------- ------- ------- --- ---
Disk 0 Online 223 GB 0 B
Disk 1 Online 931 GB 0 B
I appreciate any advice.
Best Answer
You posted in a comment: "Currently it appears to be mission impossible." Well, here is an example question, where an user had Windows installed to BIOS boot from an external drive on a 2012 Mac.
I believe your model Mac is suppose to BIOS boot Windows 10. You have a BIOS booting Windows 10 installed on the internal drive. You should probably install Windows 10 to BIOS boot from an external drive. The instructions given in your link are for installing an EFI booting Windows on an external drive.
BIOS booting Windows installations can only access the first 2.2 TB of the installation drive, when the sector size is 512 bytes. The may be a problem since your external HDD is 5 TB in size.
The Boot Camp Assistant should be able to create a USB flash drive Windows 10 installer. This installer should be bootable on your Mac. You could use this installer to try and install Windows 10 on the external drives. These drives will need to be either MBR partitioned or hybrid partitioned like the internal drive.
UPDATE
User Cordvision posted the question Big Sur: Booting Win10 from SSD and Disable Internal Drive. This question documents how a firmware update included with macOS has resulted in problems BIOS booting Windows from external drives. I found that on my 2013 iMac the Mac Startup Manager will not always display an icon or the correct icon for an external BIOS bootable drive. Also, when choosing to BIOS boot from an external drive, the Mac may instead try to BIOS boot from a different drive. To overcome this limitation, I installed the rEFInd Boot Manager. This is a free product.
Installing BIOS Booting Windows 10 on USB HDD Using 2013 iMac
These instructions will probably only work with 2012 though 2014 Macs.
I do not have the same hardware as you have. This is as close as I can get. I am also using a wireless apple keyboard and mouse. I would recommend using a wired Apple keyboard and mouse during the installation. If you have any questions about what a step does, you probably should first ask for an better explanation.
I have Catalina, High Sierra and a BIOS booting Windows 10 installed on the internal HDD. Windows 10 is installed in the partition with the identifier
disk0s3
. The external USB drive does not have any operating systems installed. I will be installing a BIOS booting Window 10 the partition with the identifierdisk2s3
. Currently, this partition contains an ExFAT formatted volume.The steps I used to install Windows 10 to an external HDD are given below.
Download and install
gdisk
from the SourceForge website GPT fdisk. This is a free product. First, download to yourDownloads
folder. Next, enter the command below in a Terminal application window to remove the quarantine.Finally, use the Finder application to open the downloaded file and install
gdisk
.Use the
gdisk
command to insure the USB drive is hybrid partitioned. Below is what I entered in a Terminal application window. Note: According to Wikipedia, APFS partitions do not have a defined MBR hex code, so I choose to use the hex codeda
.Below is the output, when I entered the above.
Use the Boot Camp Assistant application to create a Windows 10 installer flash drive. Below is an image of my selection from Boot Camp Assistant included with Catalina. Do not use the Boot Camp Assistant to install Windows 10. Only create the flash drive installer from the download Windows 10 ISO file. This file can be download from this Windows website. The file I downloaded was named
Win10_20H2_English_x64.iso
.When finished, check to see if the root folder on the flash drive contains the file named
AutoUnattend.xml
. If found, change the name toNoAutoUnattend.xml
.Download and install the rEFInd Boot Manager from the SourceForge rEFInd website. Here I will assume the downloaded zip file was expanded to the folder
refind-bin-0.13.2
. If you have a different folder, then make the appropriate substitutions. Note: Thediskutil
commands may state the volume is already unmounted and therefund-install
script will produce an error message with respect to either thesed
orbless
command.Shutdown the Mac. Remove all external drive except the Windows 10 installer flash drive. Start the Mac and immediately hold down the option key until the Mac Startup Manager icons appear. Highlight the external drive icon labeled
EFI Boot
, then select the arrow under this icon. This will boot to Mac from the Windows 10 installer flash drive. Below is a image similar to the external drive icon you will see.The first window to appear should be similar to the one shown below. At this point, you can plug in the drive where Windows will be installed.
Proceed as one would for a GUI installation of Windows. When a window similar to the one shown below appears, press the shift+F10 key combination.
The result should be the appearance of the Command Prompt window shown below.
Enter the command given below to determine the drive letters.
In this example, drives
d:
andf:
were determined to be the ExFAT volume on the Windows installer flash drive and the ExFAT volume where Windows will be installed, respectively. If your drive letters are different, then make the appropriate substitutions in the remaining steps.If necessary, enter the command below to get the names of the available Windows installations.
In this example, the name
Windows 10 Pro
will be used. If you choose a different name, then make the appropriate substitution in the following step.Enter the following commands to begin installing a BIOS booting Windows 10.
When finished , close the Windows Setup window by clicking on the red box with the X mark. In the next window, select
Repair your computer
, thenTurn off your PC
. After the Mac turns off, remove the flash drive.Start the Mac and immediately hold down the option key until the Mac Startup Manager icons appear. Highlight the internal drive icon labeled
EFI Boot
. Below is a image similar to the internal drive icon you will see.However, if you installed rEFInd to an external drive, then you should instead highlight the external drive icon labeled
EFI Boot
. Below is a image similar to the external drive icon you will see.Next, hold down the control to change the straight arrow to a circular arrow. Select this circular arrow to boot the Mac to the rEFInd Boot Manager. With the icon shown below highlighted on the rEFInd display, press the return key. If the icon does not appear, then press the esc key to refresh.
Finish installing Windows 10. The computer will automatically reboot to rEFInd, then Windows 10 on the external drive. When finished installing Windows 10, plug in the Windows 10 installer flash drive and execute the
Setup
application in theBootCamp
folder on the flash drive. Afterwards, eject and remove the Windows 10 installer flash drive before restarting the Mac.There should be an Apple Software Update application installed on your Mac. Execute this application to get updates from Apple. I would recommend installing any updates to Apple Software Update first.
Finally, check with Windows Update for any additional (optional) driver and other software updates.
Additional References
Man page of gdisk
Man page of refind-install
DISM Image Management Command-Line Options
DISM Driver Servicing (.inf) Command-Line Options
BCDBoot Command-Line Options
Bootsect Command-Line Options
BIOS/MBR-based hard drive partitions
The rEFInd Boot Manager
The rEFInd Boot Manager: Configuring the Boot Manager
The rEFInd Boot Manager: Using rEFInd