Hypervisor to the Rescue!

I recently asked my fifteen year old daughter what she thought hypervisor was. Her response was pretty funny.

“Is that one of your silly comic book characters, Dad?”

To that I laughed and said no, not exactly. However, the whole idea of hypervisor being a “superhero” got me to thinking (always a dangerous path for me). In a lot of ways in the eyes of many organizations and systems administrators, hypervisor has become something of a superhero. It’s minus the cape, bright spandex, and catch phrase, but a super hero never the less.

In the virtual superhero world there are actually two hypervisors. The first is the powerhouse superhero (much like Superman) of the two and is referred to as type 1. Type 1 boasts the power to be the “native” or “bare-metal” software that runs directly on a given hardware platform and along with many other powers has the ability to act as an operating system control program. It can do this all while residing underneath the operating system (OS) on the bare metal of the server hardware itself, which in itself is a powerful ability. VMware Virtual Infrastructure and XEN are just two of the “secret” identities that hypervisor type 1 goes by in normal society.

Type 2 hypervisor is the second of these superheroes. If type 1 is Superman, then type 2 is Batman. It doesn’t possess all the cool powers, but it does have some nifty gadgets in its “utility belt”. Type 2 lacks the nifty super ability to perform its duties underneath the OS, but still is able to get the job done of putting “rogue” servers in their place by running on top of a “host” OS such as Windows or Linux. In normal society type 2 hypervisor has several “secret” identities including VMware Server, VMware Workstation, Microsoft Virtual Server, and Microsoft Virtual Workstation.

Now you might ask how type 1 and type 2 hypervisors are super heroes. What do they possess that goes far beyond the realm of mortal programs and operating systems? The answer to this is simple. They both possess the ability to take one physical workstation or server and turn it into multiple workstations or servers. I run VMware Workstation 6.0 on my desktop at work. The desktop before VMware Workstation 6.0 is a 3.00 GHz, dual proc, dual core server with 5 gigabytes of RAM running Windows XP 64 Bit (yes, I haven’t upgraded to Vista… yet). With VMware Workstation 6.0 I also run four Windows 2003 R2 Standard Edition servers, two Windows XP workstations, and a Vista workstation. So, I have a total of eight separate systems running on my one workstation at the same time! Also, each of these virtual machines running my workstation is just a collection of files that can be copied and moved to other systems. Since they run “bare-metal”, or in normal terms, without the need to interact with the physical hardware of the workstation, (they instead relying on the hypervisor layer to supply them with RAM, Video Cards, Processors, Network Interface Cards (NIC), and all other hardware needed to run a system) these virtual machines can easily be ported to other workstations or servers of a completely different model, chip set, and vendor should the need arise.

How does all of this allow hypervisor to “serve(r) and protect” your friendly neighborhood systems administrator? For starters, once setup correctly, deploying a virtual server takes minutes instead of hours, saving the systems administrators time and energy and allowing he/she to focus more on other projects. Next, when properly thought out hypervisor will allow a disaster recovery plan to have all of the critical Unix, Linux, and Windows servers up and running within a matter of minutes at a disaster recovery site, potentially saving an organization millions of dollars and making the systems administrator appear to be a “superhero” in their own right. Another “serve and protect” feature is that the administration that goes with maintaining physical hardware in a datacenter is taken away by using hypervisor, be it as VMware, Xen, Virtual Iron, or Microsoft Virtual Server. If there are 10, 20, 30, or 60 servers residing on just one physical server then that leaves only one physical server for the systems administrator to maintain. Granted, that does leave just one point of failure for all those servers. However, most enterprise level hypervisor products allow and recommend an infrastructure of multiple servers to be setup in order to reduce the possibility of downtime. Some even automate the process of failover to existing servers in the event of a server failure. With proper design a virtual infrastructure has many of the same feature sets as a clustered environment and can allow for greater total uptime for the virtual servers deployed on them.

As Hypervisor (said in my best loud and commanding superhero voice) scans the horizon looking for organizations to rescue, a sense of peace and security pours through the hearts of systems administrators everywhere. Be it Type 1 or Type 2, both will assist the systems administrator in his daily routine and create a more flexible and stable environment for the organization he serves. With this peace and security organizations and systems administrators can sleep soundly at night knowing that hypervisor is on duty protecting them from the evils that lurk in the darkest corners of information technology.