If you want to boot from a bootable USB, you have to make a pass-through device.

This assumes you have USB Installer already created or an image of that installer as a file.

###Step 1: Create the Installation Media

Using hdiutil create a sparse (expanding) disk image with a size of 6GB

hdiutil create -size 8GB -fs FAT32 -volname "Win10-Install-Media" -type SPARSE ~/win10-installation-media

Next, mount the image

hdiutil mount ~/win10-installation-media.sparseimage

You will get a message that describes the layout of the drive image. Pay attention to the disk identifier as you will need it for the next step.

###Copy the install USB to the image

dd if=/path/to/USB/Installer of=/dev/disk#

The newly created image will need to be unmounted for the next step, so go ahead an unmount the disk.

diskutil unmountDisk /dev/disk#

Step 2: Create the VMDK

To do this, we are going to use VirtualBox's "raw hard disk access" to create a pass through to the newly created drive image.

The syntax of the command is as follows:

VBoxManage internalcommands createrawvmdk -filename </path/to/file>.vmdk -rawdisk /dev/disk#

So, for our purposes, the command would be (note the escaped spaces)

VBoxManage internalcommands createrawvmdk -filename ~/Windows\ 10\ Install.vmdk -rawdisk /dev/disk#

The VMDK will be a very small file that simply points to disk you created in Step 1. Now you can attach the VMDK to your VM and boot from it.

If you want to boot from a bootable USB, you have to make a pass-through device.

This assumes you have USB Installer already created or an image of that installer as a file.

Step 1: Create the Installation Media

Using hdiutil create a sparse (expanding) disk image with a size of 6GB

hdiutil create -size 8GB -fs FAT32 -volname "Win10-Install-Media" -type SPARSE ~/win10-installation-media

Next, mount the image

hdiutil mount ~/win10-installation-media.sparseimage

You will get a message that describes the layout of the drive image. Pay attention to the disk identifier as you will need it for the next step.

Copy the install USB to the image

dd if=/path/to/USB/Installer of=/dev/disk#

The newly created image will need to be unmounted for the next step, so go ahead an unmount the disk.

diskutil unmountDisk /dev/disk#

Step 2: Create the VMDK

To do this, we are going to use VirtualBox's "raw hard disk access" to create a pass through to the newly created drive image.

The syntax of the command is as follows:

VBoxManage internalcommands createrawvmdk -filename </path/to/file>.vmdk -rawdisk /dev/disk#

So, for our purposes, the command would be (note the escaped spaces)

VBoxManage internalcommands createrawvmdk -filename ~/Windows\ 10\ Install.vmdk -rawdisk /dev/disk#

The VMDK will be a very small file that simply points to disk you created in Step 1. Now you can attach the VMDK to your VM and boot from it.

If you want to boot from a bootable USB, you have to make a pass-through device.

This assumes you have USB Installer already created or an image of that installer as a file.

###Step 1: Create the Installation Media

Using hdiutil create a sparse (expanding) disk image with a size of 6GB

hdiutil create -size 8GB -fs FAT -volname "Win10-Install-Media" -type SPARSE ~/win10-installation-media

Next, mount the image

hdiutil mount ~/win10-installation-media.sparseimage

You will get a message that describes the layout of the drive image. Pay attention to the disk identifier as you will need it for the next step.

###Copy the install USB to the image

dd if=/path/to/USB/Installer of=/dev/disk#

The newly created image will need to be unmounted for the next step, so go ahead an unmount the disk.

diskutil unmountDisk /dev/disk#

Step 2: Create the VMDK

To do this, we are going to use VirtualBox's "raw hard disk access" to create a pass through to the newly created drive image.

The syntax of the command is as follows:

VBoxManage internalcommands createrawvmdk -filename </path/to/file>.vmdk -rawdisk /dev/disk#

So, for our purposes, the command would be (note the escaped spaces)

VBoxManage internalcommands createrawvmdk -filename ~/Windows\ 10\ Install.vmdk -rawdisk /dev/disk#

The VMDK will be a very small file that simply points to disk you created in Step 1. Now you can attach the VMDK to your VM and boot from it.

If you want to boot from a bootable USB, you have to make a pass-through device.

This assumes you have USB Installer already created or an image of that installer as a file.

###Step 1: Create the Installation Media

Using hdiutil create a sparse (expanding) disk image with a size of 6GB

hdiutil create -size 8GB -fs FAT32 -volname "Win10-Install-Media" -type SPARSE ~/win10-installation-media

Next, mount the image

hdiutil mount ~/win10-installation-media.sparseimage

You will get a message that describes the layout of the drive image. Pay attention to the disk identifier as you will need it for the next step.

###Copy the install USB to the image

dd if=/path/to/USB/Installer of=/dev/disk#

The newly created image will need to be unmounted for the next step, so go ahead an unmount the disk.

diskutil unmountDisk /dev/disk#

Step 2: Create the VMDK

To do this, we are going to use VirtualBox's "raw hard disk access" to create a pass through to the newly created drive image.

The syntax of the command is as follows:

VBoxManage internalcommands createrawvmdk -filename </path/to/file>.vmdk -rawdisk /dev/disk#

So, for our purposes, the command would be (note the escaped spaces)

VBoxManage internalcommands createrawvmdk -filename ~/Windows\ 10\ Install.vmdk -rawdisk /dev/disk#

The VMDK will be a very small file that simply points to disk you created in Step 1. Now you can attach the VMDK to your VM and boot from it.