Custom resolutions to Mac OSX guest in VirtualBox

You might notice that not all resolutions in a virtual OS X machine are listed. In order to change the resolution to something that actually uses your unnecessarily large monitor, do the following.

Method -1

If you installed Mac OS X by any of the hacked (hackintosh) ISO files, then do this first. ( This works for original retail DVD installations also)

You could see com.apple.Boot.plist file in /Extra folder. Before continue the next steps, first edit this file under /Extra with mentioned strings in step 3.

This may give the required resolution without editing the file under /Library/Preferences.

If this doesn’t work then modify com.apple.Boot.plist under /Library/Preferences as shown below Increase Mac OS X Snow Leopard Virtual Machine Screen Resolution in VirtualBox

Start the Virtual Machine.
Open /Library/Preferences/SystemConfiguration/com.apple.Boot.plist in Text editor.
Type: (1280x1024x32 – is your option. Type the correct screen resolution which matches your monitor.)

Graphics Mode <string>1280x1024x32</string>

Select Save As in Text editor file menu and save it on desktop or somewhere else. Make sure to save with same .plist file. ( Remove the tick 'if no extension is provided use .txt')
Now, copy or drag com.apple.Boot.plist file from desktop to /Library/Preferences/SystemConfiguration/ or /Extra location where ever it needs to be replaced. Enter Mac root (admin) password to authenticate replacing file.

That’s it. Restart the Mac Virtual machine. By default Mac OS X will go to the screen resolution you set up com.apple.Boot.plist. Check it by going to ‘Display’ under ‘System preferences’.

Method -2

Try this method if method 1 fails. This is method to modify VirtualBox settings for specific virtual machine. Close VirtualBox completely and run following command:

VBoxManage setextradata "vmname" CustomVideoMode1 1550x768x32

“vmname” – Excact virtual machine name of Mac OS X. If the name has spaces, you must use quotes.

The above command will modify XML file of Virtual machine. Just boot and see whether its working.

If not, while booting at the EFI boot loader screen, type;

“Graphics Mode”=“1280x800x32” and press Enter.

Always better to give the same screen resolution size mentioned in com.apple.Boot.plist file.

Method -3

This is similar to method 2, but slighlty different.

Execute this command in VirtualBox folder:

VBoxManage setextradata "vmname" VBoxInternal2/EfiGopMode 3

“vmname”– Excact virtual machine name of Mac OS X. If the name has spaces, you must use quotes.

No 3 – this is the number of video modes. Only 5 resolutions are supported:

  0 – 640×480
  1 – 800×600
  2 – 1024×768
  3 – 1280×1024
  4 – 1440×900

Or you can add a string on Virtual machine’s XML file to execute this command every time while machine is coming up.

<ExtraDataItem name="VBoxInternal2/EfiGopMode" value=”3″>