The advent of virtualization technology has not only simplified the way businesses manage workloads, but it has also made it easier to carry out offsite tasks, even if they’re not in the same geographical area.
In such instances, maintaining various computers complicates the organizational structure and also raises operational costs. Wasting money is not a big deal if you’re the U.S. government because it can just print its own money. But you are most likely not the U.S. government, so you would have a problem going massively into debt and putting everyone at risk.
This is where server virtualization comes into play, with the capacity to run various independent virtual OS on one physical server system. Let’s take a closer look at what this technique actually is, and how it affects you.
Server virtualization explained
The technique used to run numerous independent virtual OS on a single physical machine is known as server virtualization. Basically, it’s a method that maximizes your physical resources for maximization of hardware investment. When you adopt virtualization technology, you enjoy greater server density.
However, contrary to popular belief, there is no change in the total computing power; the minimal decrease that it experiences is due to overhead. No, this has nothing to do with too many office assistants on the payroll or too much money spent on ink and cartridges!
You can unleash the full potential of this hardware (which almost happened at the end of Transformers II with the sun harvester, which would have been terrible for the planet and humanity!) through an increase in the number of logical OS being hosted. This reduces the maintenance costs and hardware acquisition by a considerable degree, resulting in huge savings for your business.
What does server virtualization entail?
Server virtualization may be carried out in one of three ways:
- Full virtualization
- Virtualization at the OS layer
- Paravirtual machine system
Understanding virtualization means having knowledge about each of these processes. So let’s begin:
- Full virtualization: This virtualization model allows every guest to run as per the virtual limitation set down by the hardware layer. This enables the virtual guest OS to run without any sort of modifications. This is a total simulation of the true hardware that allows the functioning of guest software. The guest will have no idea regarding the proprietor OS. A hypervisor coordinates all instructions for the CPU and validates every instruction sent by the CPU. It also handles executed code in the need of extra privileges.
- Virtualization at OS layer: Here all the virtualized environments remain isolated from the other guests, which means any breach or failure in one partition is unable to affect the other partitions. In such server virtualizations, the host tends to run a kernel of single OS and exports OS by assigning it to every guest OS. Virtual guest machines can make use of the same OS as the host. This assists in overhead of CPU usage since the distribution architecture gets rid of system calls in between the different layers.
- Paravirtual machine: All guest models in the paravirtual machine model have been modified for the sole purpose of running in such a virtual environment. This is commonly termed “porting,” and helps users make use of a privileged system, which is called and needed sometimes.
When is it time for server virtualization?
Any application that is capable of low- to medium-scale usage can benefit greatly from server virtualization. It is a bad idea for virtualization to be used in the case of high-performance apps where one or multiple servers must be clustered together to meet the minimum performance needs of a specific application.
There are many users who believe that high numbers involving the utilization of your CPU is indicative of good hardware usage. However, you must never take this advice to the extreme where the responsiveness of the app becomes excessive.
- Recommendations: If you can, don’t let your server ever exceed more than 50 percent of the CPU utilization at the time of peak loads. Moreover, you must never allow the app response time to cross a reasonable service-level agreement. The majority of modern servers meant for in-house server responsibilities uses 1 percent to 5 percent of the CPU power. Though running eight different OS on one physical server would raise the peak CPU usage to almost 50 percent, the average is going to be a lot less as the valleys and peaks of the virtual OS sometimes cancel each other out.
Despite the CPU overhead in most virtualization processes being minimal, input or output (I/O) overhead for networking and storage throughput is a different ballgame. For servers that have hardware I/O needs or high storage, it is better to run them on metal even if a virtual environment is capable of meeting their CPU requirements.
Challenges
Virtualization of a server does provide numerous advantages, but it might not be a fabulous idea to place all the critical servers into one physical server. The solution is to ensure that a single service isn’t in charge of just one server. You do not want to put all your eggs in one basket, right?
A single server may be run on two physical servers and be totally redundant. Some services are comparatively simple to cluster as they can easily be switched out when one server fails. In the event of a single physical server failure, the other virtual server present on the same physical server can automatically handle the rest of the load. Through the integration of various physical servers, such essential services are never down from just a single hardware malfunction.
What happens with more complex servers?
You may use clustering services to synchronize two separate logical servers hosted across dual physical servers. Such a technique might result in a bit of downtime during transition, but virtualization isn’t to blame; instead, it’s the outcome of the difficulty of clustering, which needs sufficient time to transition.
You can also handle these complicated services by migrating the virtual server from the main physical server to the secondary physical server. For this to work, however, a constant synchronization of memory must take place from one physical server to another, which leaves the door open for a failover within milliseconds while every service stays functional.
Server virtualization definitely requires lots of consideration along with a well-formulated plan. However, when implemented properly, your business is going to reap the benefits in many ways over the long term. While figuring out how you can virtualize your business, you must have an idea about how much money and time is being spent on hardware and software, energy, maintenance, and so on.
In the end, there are numerous reasons why you should make an effort to understand and implement server virtualization in your business. Like most business decisions, it all boils down to a trade off between money and practicality.
