Install macOS Sierra on VirtualBox?

Installing macOS as a VM in VirtualBox

These instructions will guide you through the process of creating and using bootable media to install macOS in a VirtualBox VM.

Pre-Requisites

• Installer for for macOS (El Capitan, Sierra, High Sierra, etc.)
• VirtualBox 5.0+ (may work with older versions, but not tested)
• Newly created macOS VM created with standard settings (EFI, blank 60GB SSD, 128M video memory, 3D acceleration, 4GB RAM)

We are going to use the createinstallmedia utility included with the macOS Install App to create a USB image. However, there's nothing that says it must be a physical USB device and not a disk image instead. For this we are going to use VB's ability to access a "raw" drive through a VMDK which will act as a pass-through device that VB can recognize and mount.

In the steps below, assume the working directory is the user's home (~/).

Step 1: Create the Installation Media

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

hdiutil create -size 6GB -fs HFS+ -volname "macos-installation-media" -type SPARSE ~/macos-installation-media

Next, mount the image

hdiutil mount ~/macos-installation-media.sparseimage

You will get a message that looks similar to the one below. Pay attention to the disk identifier as you will need it in Step 2. In my environment, mine was disk7 your's will likely be different.

/dev/disk7            GUID_partition_scheme
/dev/disk7s1          EFI
/dev/disk7s2          Apple_HFS                       /Volumes/macos-installation-media

Finally, use createinstallmedia from the macOS Installer to create the installation image:

sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/macos-installation-media --applicationpath /Applications/Install\ macOS\ Sierra.app/

Allow it to finish. When it's done it will automount the new Volume and you should see it on your Desktop.

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

diskutil unmountDisk /dev/disk7

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 ~/Install\ macOS\ Sierra.vmdk -rawdisk /dev/disk7

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.

Add the VMDK to your VM and Boot

Before you can add the newly created VMDK to your VM, you need to take ownership of it. Since it was created using sudo, root has ownership and rights. Be sure to replace "joeuser" with your username in the command example below:

sudo chown joeuser:staff Install\ macOS\ Sierra.vmdk

Using the VirtualBox GUI, select the desired VM, click Settings, click Storage, click Add Hard Disk button, select Choose existing drive, and then select the VMDK file you just created.

Boot your VM. VirtualBox will automatically find the bootable volume and begin the installation process.

I realize the OP was asking about Sierra. However, the user Arien posted a duplicate question where High Sierra was to be installed in VirtualBox. This prompted me to post this answer here.

The answer is to install in the virtual machine the same as a physical Mac. However, the devil is in the details.

Hardware and Software used to test this answer:

iMac (21.5-inch, Late 2013)
macOS Catalina, Version 10.15.4
macOS High Sierra, Version 10.13.6
VirtualBox 6.1.4 r136177 (Qt5.6.3)

The steps are given below.

1. Download High Sierra.
2. Create a flash drive installer.

3. Create a virtual machine. Use the defaults for High Sierra, unless you see a need for a change. For example, I made the following changes.

   • Increased the drive size to 200 GB.
   • Selected 4096 MB for the memory size.
   • Upgraded to USB 3.0.
   • Disconnected the ethernet cable.
   • Attached the network adapter to Bridged Adaptor..

   Note: Do not upgrade to USB 3.0 unless your Mac actually has USB 3.0 or higher.

4. Add the High Sierra USB flash drive to the list of USB Device Filters. Usually, the name of the USB flash drive will by something cryptic. In my case, the name was GenericU3 Mass Storage [0002].

   

5. Using the Finder, eject the flash drive, then use VirtualBox to start the virtual machine.

   Note: If you get window similar to the one shown below, then click on the Cancel button.

   

   Note: With this version of VirtualBox, you can have High Sierra boot from APFS volumes.

6. After installation has completed and the virtual machine has shutdown, remove the High Sierra USB flash drive installer from the USB device filters.

Manually Booting from the USB Flash Drive

It is possible for a variety of reasons that you will boot to the UEFI Interactive Shell, as shown below.

To boot from the virtual optical drive, enter the command shown below at the Shell> prompt.

FS0:\System\Library\Coreservices\boot.efi

Installing High Sierra without Using a Flash Drive

I realize the OP was asking about Sierra. However, the user Arien posted a duplicate question where High Sierra was to be installed in VirtualBox. This prompted me to post this answer here.

The answer is to install in the virtual machine the same as a physical Mac. However, Arien does not have a flash drive and wants to do without. I should mention Allan`s answer would also appear to work. Although, I did not verify this.

Hardware and Software used to test this answer:

iMac (21.5-inch, Late 2013)
macOS Catalina, Version 10.15.4
macOS High Sierra, Version 10.13.6
VirtualBox 6.1.4 r136177 (Qt5.6.3)

The steps are given below.

1. Download High Sierra.

2. Open the Disk Utility. From the menu bar select File→New Image→Blank Image. Enter the following, then click on the Save button. When finished, click on the Done button.

   

3. This Apple website explains how to create a Flash Drive installer. Instead of using a flash drive, the sparse disk image created in the previous step will be substituted. Basically, enter the command given below in a Terminal application window.

   sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume
   

    
   When finished, eject the volume labeled Install macOS High Sierra.

4. Create the file Install macOS High\ Sierra.iso from the file Install macOS High Sierra.sparseimage by entering the commands shown below.

   cd ~/Desktop
   hdiutil makehybrid -o Install\ macOS\ High\ Sierra.iso Install\ macOS\ High\ Sierra.sparseimage -hfs -iso -hide-iso '*'
   

    
   When finished, you can delete the file Install macOS High Sierra.sparseimage.

5. Create a virtual machine. Use the defaults for High Sierra, unless you see a need for a change. For example, I made the following changes.

   • Increased the drive size to 200 GB.
   • Increased the number of processors to 2.
   • Selected 4096 MB for the memory size.
   • Disconnected the ethernet cable.
   • Attached the network adapter to Bridged Adaptor..

6. Put the disk file Install macOS High Sierra.iso in the virtual optical drive.

7. Start the virtual machine.

   Note: If you get window similar to the one shown below, then click on the Cancel button.

   

8. You will boot to the UEFI Interactive Shell shown below.

   

   To boot from the virtual optical drive, enter the command shown below at the Shell> prompt.

   FS0:\System\Library\Coreservices\boot.efi
   

   Note: With this version of VirtualBox, you can have High Sierra boot from APFS volumes.

9. When finished installing. You can remove the disk file Install macOS High Sierra.iso from the virtual optical drive. If you wish, you can delete this file.