I am trying to install Windows 10 on a partition with this Virtualbox method, where I create a vmdk link to the partition and use it as the drive, run the installer and then reboot.

This worked fine on a device running Mavericks, but on one with El Capitan does not work, and prints out a VERR_ACCESS_DENIED

VBoxManage internalcommands createrawvmdk -filename ~/RawWinDisk.vmdk -rawdisk /dev/disk0 -partitions 1,4

This is supposed to make the vmdk file. I did do a chown to /dev/disk0, disk0s1 and disk0s4. I also tried a chmod -R 777 on them to see if it helped, but it still did not work. Running command as sudo does not work either.

  • 1
    guessing you hit SIP. Did you try with it off?
    – Tetsujin
    Nov 27 '15 at 21:43
  • @Tetsujin Please explain what SIP is. I didn't yet meet up with such term
    – John K
    Nov 27 '15 at 21:44
  • System Integrity Protection - see apple.stackexchange.com/questions/208478/…
    – Tetsujin
    Nov 27 '15 at 21:45
  • I'm trying to reproduce this on 5.0.10 r104061 - I don't seem to be wrapping my brain around why the Mac raw devices are being used by the guest OS.
    – bmike
    Nov 27 '15 at 21:48
  • 1
    Ah, glad it helped - putting together a [rather short] answer :)
    – Tetsujin
    Nov 28 '15 at 14:19

I think you may be hitting El Capitan's System Integrity Protection [SIP] which is preventing access..

Borrowed from How do I disable System Integrity Protection (SIP) AKA "rootless" on OS X 10.11, El Capitan? ...

Apple's documentation covers disabling SIP, About System Integrity Protection on your Mac.

An article on lifehacker.com lists these steps:

  1. Reboot your Mac into Recovery Mode by restarting your computer and holding down Command+R until the Apple logo appears on your screen.
  2. Click Utilities > Terminal.
  3. In the Terminal window, type in csrutil disable and press Enter.
  4. Restart your Mac.


sudo chown $(USER) /dev/disk0s4
sudo chmod 660  /dev/disk0s4
chmod 600 ~/RawWinDisk.vmdk

after each MacOS restart I need again chown /dev/disk0s4 to start Windows VM normally.

  • I had to use ${USER} and /dev/disk2to get my external USB drive with the OSX Install files working. Nov 7 '19 at 8:26

in case this helps anyone, I have been booting my bootcamp partition via vbox since probably OSX Lion. when SIP came along, I had to adjust my vbox run script to do the chmod's as described elsewhere, but today I had to re-create my pointer VMDK (VBoxManage internalcommands createrawvmdk...) because my drive numbering changed (/dev/diskN) and I could not without temporarily disabling SIP... no chmod'ing would make a difference. After creating the new VMDK, I reenabled SIP, and am back to chmod'ing before virtual startup/after each host reboot. HIH

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