Almost... so close... then fail

Discussions related to using VirtualBox on Mac OS X hosts.
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OldBaldGuy
Posts: 1
Joined: 26. Sep 2022, 21:14

Almost... so close... then fail

Post by OldBaldGuy »

Following a number of online instructions to use VirtualBox to create an external SSD to allow a bootcamp boot of Windows 10 on a MBP running Catalina.
One set says to format the SSD as MBR , the other as GUID.
At least the GUID creates the needed EFI partition , but the second partition is
However , when the actual Windows installation gets to the point where the Win 10 installer asks for where to perform the install , I see the two ( sometimes three ) partitions and formatting partition 2 is not available. It is my understanding that it has to be NTFS , however it's not.
As I said , almost , so close. Now stuck.
mpack
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Posts: 39156
Joined: 4. Sep 2008, 17:09
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Mostly XP

Re: Almost... so close... then fail

Post by mpack »

OldBaldGuy wrote:Following a number of online instructions to use VirtualBox to create an external SSD to allow a bootcamp boot of Windows 10 on a MBP running Catalina.
One set says to format the SSD as MBR , the other as GUID.
VirtualBox doesn't care what filesystem you use for a host drive. It's a host drive. Locating app data files there doesn't stop it being a host drive.

Also VirtualBox and Bootcamp are two entirely separate features. I can't see how one would help with setting up the other.

If you want to install a Windows VM in VirtualBox then ignore "online instructions" and instead just read what's in chapter 1 of the VirtualBox user manual.

If you have some reason for wanting to make it more complicated then please explain what your actual goal is.
scottgus1
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Joined: 30. Dec 2009, 20:14
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows, Linux

Re: Almost... so close... then fail

Post by scottgus1 »

I'll add in one thing: Stuff that happens in the VM stays in the VM. So if you install an OS in a VM, all that activity is only happening inside the VM's disk file, which as Mpack points out, resides as a file on the host drive. The OS in the VM will format the contents of the disk file as it needs. Whatever the host disk is formatted as is not seen or cared about by the VM OS.

So you can format your external or internal physical drive(s) whatever you and the host OS want. Windows will format the VM's disk file as NTFS. The VM's formatting will not interfere with the host formatting, since the VM's disk is only a file on the host drive.
OldBaldGuy wrote:when the actual Windows installation gets to the point where the Win 10 installer asks for where to perform the install , I see the two ( sometimes three ) partitions and formatting partition 2 is not available.
I have seen this happen when a Windows install as been run partway, then it gets restarted from the beginning. Windows typically makes three partitions: an EFI System Partition, a regular boot/data partition, and a recovery partition. These partitions will still be visible if the install is restarted. If you did want to restart the Windows install, then you need to delete these partitions using the commands in the Windows installer then let Windows remake them in the new install.
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