[SoaS] Another way to use VirtualBox and SoaS on a Mac

[Gary C Martin]

Hi folks,

Just thought I'd bounce another possible approach pass the list for using a regular Soas loaded USB stick on Mac OS X, this one has the obvious benefit of allowing you to use the same USB stick on different machines/locations. Now, VirtualBox's BIOS does not support booting from a USB stick unfortunately, but as it turns out there are some hidden ways to make VirtualBox boot what the documentation refers to as "raw disks" rather than regular VM disk images (Page 135 in the VB manual, 9.10 Using a raw host hard disk from a guest).

*** Caviate lector, the USB stick I'm using does not seem to be saving changes between uses, I'm not sure if this is an issue with the stick I made, or this approach ***

Here's the steps:

1) Plug in your soas-2-blueberry USB stick

2) In a terminal type:

	df

You should see a line that says something like the below, make a note of the /dev/disk1 it may be different on your Mac depending what hardware you have:

	/dev/disk1       1206080   1206080         0   100%    /Volumes/soas-2-blueberry

3) Mac OS X must not auto mount the USB. If it does you can't create the needed vmdk to reference it (you'll get an "VERR_DEV_IO_ERROR"), and the documentation warns of potential file corruption if you allow both a host and guest OS to tinker with the same raw disk at the same time. The rather naughty trick is to go edit your fstab to prevent the specific stick from auto-mounting [I hope to find a non techy replacement for this step]:

	sudo vim /etc/fstab

...and append the line:

	LABEL=soas-2-blueberry none cd9660 ro,noauto 0 0

4) Now make sure to eject the USB volume from your desktop; unplug your soas-2-blueberry USB stick; plug it back in again to check. It should _NOT_ appear on your desktop this time.

5) In Terminal run the below VirtualBox command, modifying the .vmdk save location, and your /dev/disk1 as needed. This will create a tiny little vmdk file that holds the description of the USB stick, and register it with the VB media manager so it's available as a disk:

	VBoxManage internalcommands createrawvmdk -filename /Users/gary/Desktop/soas-2-blueberry.vmdk -rawdisk /dev/disk1 -register

6) In VirtualBox create and configure a VM as normal, you should see the soas-2-blueberry.vmdk listed as an available existing disk.

7) All done, time to boot...

Regards,
--Gary

P.S. There's another way of getting VirtualBox to boot the USB stick on the Mac, but I'll give it a couple of tries before reporting back here.