*Application

               virtualization does not exist**               (november 25 2007)*

Last     week I was a speaker on the virtualization seminar of Heliview.

               Nowadays I have to explain that application virtualization does not exist

               on a daily basis, therefore this was a great occasion to tell it to more

               than a hundred people at the same time. It is not that

               difficult, but even my nearest colleagues, who get the message swung to their

               heads more than often, have a hard time understanding.

               Why is it so hard? It's because few people know exactly how the components of a system relate

               to each other. I will explain it once again. "Virtually"

               according to the dictionary is "appears to be present/seems to be present". Vmware or Xen work by

               making hardware "seemingly present" that's easy enough. The term "virtual server" is for this reason misleading, because the server operating system installed on that virtual hardware is not virtual. Thats

               a really present 'file - or database server. Vmware and Xen are therefore      an example of hardware virtualization.

               What follows after hardware? Not application. There's something in between. That's

               the operating system. We'd rather not think about that one, it runs all those

               nice and necessary applications, but recognising it as a separate entity is something else. That's because it is not touchable. Your capacity to think in abstractions is needed now.     When

               the operating system is virtualized it appears to the application the

               same way as hardware does to the Operating system when run on VMware/Xen. The operating system remained

               present as a reality, and wasn't "seemingly present". In the case of

               operating system virtualization the operating system appears to be present.

               For the application there nothing suspicious, it still talks the

               same code to the operating system, not bothered by the operating system

               being virtual or not.

               Time

               for the examples. Java. The Java virtual machine. You install Java (the

               Java virtual machine) on your operating system, which can be linux,

               windows or whatever. Each java-application considers Java to be the operating

               system, and send tasks in Java code. The Java vitrtual machine translates

               that code to the code which can be interpreted by the operating system that is

               ran underneath. (Or the one controlling the hardware). The Java virtual machine

               masks the real operating system for the java-application. Java-applications

               use a operating system that "seems to be present" and do not need, as a result,

               have to be made for linux or windows

               specifically.

               Another

               one: SVS, software virtualization services. A

               piece software is installed on the real operating system. When an

               application is installed svs takes care that the real registry is not shown to               the application, only a screened part of it. Thus it seems for the application as if there are no other applications in its wake. It thinks

               it's on it's own on the operating system. The "seems to be present" operating system.

               Softgrid:

               You get a client-application. This client application is used by the windows

               applications that are sent by a type of fileserver. As a result of which

               these applications run in the client. The Windows application is not aware

               of any virtualization. They still run the same way as if they were sending

               its code to a real installed operating system. The application is not

               seeming to be present, the operating system is! Thus, what is called

               "application virtualization" is actually operating system

               virtualization. Capice?

               Why am I all alone in having this insight? Because you are bombarded by marketing

               machines which have discovered that virtualization is hip. Which must be milked dry

               completely, ofcourse. That a lie is not an obstacle does not seem to be an

               issue. You can freely be poisoned with this propaganda. It's the money

               talking now and commercial interests prevail. Marketing has no definition of virtualization other then $$$