… or two layers of virtualization.
First of all, a quick reminder. VirtualBox must be installed on top of an OS whereas Oracle VM Server is a bare-metal and then it has to be installed instead of the OS, making the machine dedicated to the virtualization.
It’s well known that bare-metal virtualization software like Oracle VM or VMWare vSphere (or vSphere Hypervisor on free market) is much more robust and compliant for enterprise use.
As far as I understood from several Oracle people across forums or threads like as this one, it was not supported... not recommended... not stable... well, not advisable at all, do not say ridiculous way of thinking. Especially that way, having Oracle VM as a VM in VirtualBox…
However, on my side, I did it several years ago when Peoplesoft started to deliver templates.
Indeed, being in lack of free server, I integrated them in VMWare Server installation (software decommissioned since then, but the principle was the same as VirtualBox) : I made an Oracle VM Server in a VMWare virtual machine to be able to test the Peoplesoft templates. Have a look there, especially at the picture :
Of course, there was absolutely no intend to use it for production or development, only for learning, training and demo purpose. I insist, I was and I’m not speaking on behalf of any company, just in my name, and that was only for learning purpose. Which is totally different than if I was speaking for Oracle.
Obviously, things are changing...
I'm probably very late on this, but I recently discovered that Oracle was providing an Oracle VM Server template for VirtualBox (http://www.oracle.com/technetwork/server-storage/vm/template-1482544.html).
Even though this is mentioned that’s only for demo with limited functionalities (no Windows guest), it really means you have now officially Oracle VM Server running in VirtualBox... What a surprise !
And the picture page 2 of the documentation is clear enough.
Well, you may argue the schema given by Oracle is nicer than mine, but they are very similar (or close to each other), aren't they ?
Ok, that's good for all, again training is important and many people were actually desperately trying to translate delivered Oracle VM templates in other virtual machine software than Oracle VM, a much lighter one and especially not on a dedicated machine such as laptop.
In the end, it was rather obvious, since VirtualBox is Oracle, why not do it themselves on their own products ?
What’s the real intend behind it ? Making Oracle VM Server known by more people ? Making it more popular ? I don’t know, but I'd say there's a dark side of this.
Since this is Oracle which gives that way of use, it will be more and more generalized. And having 2 layers of virtualization, a virtual machine (your template running on Oracle VM Server) in a virtual machine (your Oracle VM Server running on a VirtualBox) could make the entire system slow and overall (very) unstable.
Does it not sound like... Inception... a dream in a dream... ? Take care do not fall in Limbo...
Customers must stay on the proper usage of the way it should : learning purpose only.
Nothing is less sure though... as in the movie mentioned above, unplanned thing may always happen... and we never know if this is for the better... The spinning top is launched, let's see if it will stopped to spin.
addendum : it was already discussed in this thread on OTN Peoplesoft OVM Forum more than 2 years ago, and as I said “I used those Peoplesoft OVM images in Oracle VM hosted by VMWare... Yes, I know, double virtualization level”… so, nothing really new… just coming from Oracle now.