Installing Virtualbox in a Virtualbox guest OS

[Herbie]

I am using a Macbook Pro 11,3 Retina, 15 inch, Late 2013 with BootRom Version MBP112.0138.B14, SMC Version 2.19f12.

I have installed VirtualBox version 4.3.14 r95972

I am trying to put together a presentation for a group of developers on installing and using VirtualBox, and I think I have a unique situation here.

I have installed VirtualBox on my Macbook Pro, created a VM running guest OS of Windows 7 64bit. On the Windows 7 guest OS I have installed another instance of VirtualBox, making is a Guest/Host, and I want to create a VM to run a guest OS of CentOS. My problem is that I am unable to select a 64bit Linux OS for the guest OS, only 32bit is available.

I am assuming that I am just running "too deep" by going with the Host -> Guest -> Guest/Host -> Guest installation model. Can anyone offer any suggestions on this, or should I just be happy with the 32bit install because of the crazy VM in a VM situation?

I am doing this crazy install because the developers I am presenting to run Windows PC and I want to present in their environment. I tried the Mac Boot Camp install route first and almost killed my laptop in the process (not sure if it was a Mac or user issue, but I don't trust it enough to try that route again )

[mpack]

Hardly a unique situation. We've had a "sticky" discussion on the subject since 2009!

viewtopic.php?f=1&t=20589

Summary: VT-x is used by VirtualBox itself, not reflected into the guest - therefore a nested VBox can't run 64bit guests, or Win8 guests. In any case nested VMs are not supported.

[Herbie]

Good to know, thank you for the information. At least now I can leave the rest of the hair on my head and assume that I am crazy.