Quoting from below:

So what do you get with this commoditized distribution and especially
kernel? You get hot kernel updates (which can be *very* useful to
avoid downtime when updating a live, mission critical host), and
guaranteed compatibility with Oracle software (which is not a fmall
thing for a big iron Oracle server handling thousands of transactions
a second).

End quote.

The above precisely addresses my query.  I have been a long time user of 
VirtualBox after VMWare (originally from
a Stanford group if memory serves) became a strictly for-profit 
commercial approach that only administrative (not academic research by 
Faculty) computing had sufficient budget to afford.  I routinely run MS 
Windows (currently MS Win 7 pro) under VirtualBox on an EL workstation 
as a mechanism to use end-user applications that are not available under 
open systems without any necessity of dual-booting, etc.  Because 
VirtualBox source and documentation are available, I also teach from it 
so that students have a better real-world understanding of a hypervisor 
and certain types of virtualization.

However, I have not used VirtualBox in a mission-critical server 
environment.  If anyone else has experience with the Oracle pre-packaged 
VMs under VirtualBox in a distributed server environment, I would 
appreciate additional observations.  On a reasonably well provisioned 
workstation, VirtualBox running MS Win 7 (and previous MS Wins) displays 
no real end user experience degradation (long load or execute times, 
crashes, etc.).  However, a mission critical server can experience a 
very different workload than a workstation, and it is important to be 
able to predict significant end user service degradation due to the 
virtualization overhead -- particularly in real-world use (not 
simulations or highly controlled environments).

Yasha Karant

On 04/05/2014 08:29 AM, Nico Kadel-Garcia wrote:
> VirtualBox itself, I like. The authors seem to have actually read Eric
> Raymond's old essay on the "Luxury of Ignorance",  and made an
> effective user interface that does not *argue* with you, and works
> well with multiple types of server and client. I use it on a Windows
> box for best performance of games, and use VirtualBox for my
> Scientific Linux and similar environments. The use of the right "Alt"
> key rather than "Ctrl-Alt" combinations to switch away from the VM
> screen is one of my favorite bright moves from its designers.
>
> The Oracle virtual VM's are a freeware problem. Oracle has tried to
> proprietize someone Red Hat's free software and open source work,
> especially the kernel, and it would be quite difficult to bring their
> changes over to SL or other freeware rebuild environments.
>
> Oracle's own download pages point to their "public" yum server at
> http://public-yum.oracle.com/repo/OracleLinux/. Unfortunately, the
> repository is not browseable, probably to reduce the likelihood of
> people making mirrors of it. To review its contents without installing
> them, you have to set up a yum configuration and run something like
> "reposync -n -u --repoid=ol6_latest", or mirror them locally with the
> "reposync" command. This is feasible, but it's a pain, and makes
> picking and choosing awkward. And that seems to be the point. The
> source packages seem to be avaialble at
> https://oss.oracle.com/ol6/SRPMS-updates/.
>
> So what do you get with this commoditized distribution and especially
> kernel? You get hot kernel updates (which can be *very* useful to
> avoid downtime when updating a live, mission critical host), and
> guaranteed compatibility with Oracle software (which is not a fmall
> thing for a big iron Oracle server handling thousands of transactions
> a second).
>
> Scientific Linux, and CentOS, have been *very* good about making their
> work genuinely open and accessible. They've also been very good about
> labeling their modified packages as modified, with an I'm not sure I
> want to cooperate  with this sort of "we'll make the files available,
> but we won't tell you their names" sort of silliness.
>
>>> Date: Wed, 2 Apr 2014 12:04:22 -0700
>>> From: [log in to unmask]
>>> To: [log in to unmask]
>>> Subject: VMs of EL and other environments
>>> I realize that VirtualBox is separate from SL. However, Oracle has a
>>> distro based upon the same TUV that SL uses and provides a set of
>>> pre-built VMs for
>>> specific purposes - title and URL appear below. Has anyone on this list
>>> used any of these, and if so, any comments on the efficacy of such use?
>>> A reply off-list is fine if this is not a list topic. VirtualBox is
>>> available as an EL6 binary RPM for both IA-32 and X86-64, and seems to
>>> run well with no missing dependencies or crashes.
>>>
>>> Thanks,
>>>
>>> Yasha Karant
>>>
>>> Pre-Built Developer VMs (for Oracle VM VirtualBox)
>>>
>>>
>>> http://www.oracle.com/technetwork/community/developer-vm/index.html