[Info-vax] OpenVMS on x86 and Virtual Machines -- An Observation

[David Wade]

On 30/01/2019 18:57, Phillip Helbig (undress to reply) wrote:
> In article <8f9a7157-ac0c-4471-a725-ce52ffa4a86c at googlegroups.com>,
> gezelter at rlgsc.com writes:
> 
>> Traditionally, OpenVMS has been run on dedicated hardware.
> 
>> With the advent of OpenVMS on x86, there is an increasing discussion of
>> running OpenVMS x86 on various virtual machine hypervisors
> 
> Since VMS will soon run natively on x86, what is the motivation to run
> it on some sort of emulator?
> 

Well whilst others have said "virtual" is not "emulation" I would say it 
is emulation of sorts, but done at the microcode level in the chip.

As to why, well many reasons. I think for most industry the biggest 
driver is a reduction in cost. Its not just the cost of the base 
hardware. Servers need cooling and power and floor space all of which 
are expensive. Virtualization allows you to run multiple copies of an OS 
on one box. More than that most modern Hypervisors allow you to move the 
running virtual image to a different server, while its running.

This means you can load balance and really optimize your farm to the 
minimum hardware without compromising availability.

The second is that it decouples the software from the hardware. Virtual 
Machines present virtual peripheral interfaces. When you upgrade the 
hardware the OS still sees the same type of peripheral....

Dave