Using VirtualBox to use a BootCamp Windows 8.1 Partition on Mac OS X Yosemite

By | 27 June, 2015

I’ve been trying to get to the point where I can use my bootcamp partition from within Mac OS X Yosemite, (like you can do with VMWare Fusion or Parallels 10).

I’d been seeing lots of failed to boot messages and gave up a couple of times, but have found the solution finally.

** THIS IS TOTALLY AT YOUR OWN RISK, AND YOU SHOULD MAKE SURE YOU HAVE A VALID BACKUP OF YOUR WINDOWS AND MAC OSX PARTITIONS, JUST IN CASE **

Most of this was from jakehilton.com with a bit of improvisation from me.

1. Map your drive layout. Open a terminal and type:

diskutil list

result —————–

/dev/disk0
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *500.3 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_CoreStorage 438.3 GB disk0s2
3: Apple_Boot Recovery HD 650.0 MB disk0s3
4: Microsoft Basic Data BOOTCAMP 61.1 GB disk0s4

2. Make sure the bootcamp partition is unmounted, assuming of course you’re not using it.

sudo umount /dev/disk0s4

3. Amend the owners of the partitions to your current user, and allow read/write/execute permissions. We’re going to target two partitions, the EFI partition and the bootcamp partition. (my user name is daed, you should replace that with you’re user name)

sudo chmod 777 /dev/disk0s1
sudo chmod 777 /dev/disk0s4
sudo chown daed /dev/disk0s1
sudo chown daed /dev/disk0s4

4. Create a vmdk in a directory which acts as a pointer to the actual partitions. I store all my virtual hard disks in a /VMs directory.

sudo VBoxManage internalcommands createrawvmdk -rawdisk /dev/disk0 -filename /VMs/win8raw.vmdk -partitions 1,4

5. Check that the permissions are right on the vmdks that were created.

sudo chmod a+rwx /VMs/win8*
sudo chown daed /VMs/win8*

6. Create your bootcamp VM in VirtualBox.

This is where we’ve got to get the configuration right….

The trick is to set the Virtualbox VM to Windows 8.1, 2048MB RAM. Do not add a virtual drive yet. Click create.

Click on the General Properties of the VM, and go to System. Tick Enable EFI (special OSes only).

Click Storage. Remove the SATA controller. Select the IDE controller. Change the type to ICH6, now add your win8raw.vmdk to the IDE controller.

…and you should be good to go.

** NOTE. After a clean reboot of Mac OS X Yosemite, I have noticed that steps 2 and 3 may need to be redone, Virtualbox reports that the vmdk is inaccessible where actually the issue is that the /dev/disk0s1 and /dev/disk0s4 that the vmdk points to are actually inaccessible to a normal user. **