On 9/22/2010 3:14 PM, Stephen Powell wrote:
That may be true for some virtualization software, but not for all. My "day job" is as a system programmer for IBM mainframe systems, and among my duties is responsibility for a z/VM system. In z/VM, nested virtualization is not difficult, pointless, or unstable. I routinely install a new release of z/VM in a virtual machine running under the production release of z/VM, for example. There's even instructions in IBM's installation manuals for how to do this.
This is the exception that proves the rule. I still think that doing it under an AMD64 or Intel x86_64 is probably futile under the current state-of -the-art.
I know it's been done under a XEN hypervisor. I don't know about Virtualbox. If you do it and it's stable, like I asked another poster in another thread, please write a HOWTO and show everyone how it's done.
I am aware of the old MVS and all that, running DOS and CMS and so on all at the same time, but I'm a decade too young to have any experience with that. All I can say I've done is write COBOL and JCL with Report Writer under WYLBUR for a class.