Every web business needs web hosting as a starting point. Although a dedicated server has the capacity to run a project on a large scale, not all projects are large-scale projects. This together with the high cost of renting a dedicated server created a need for alternative options. Among these alternatives, Virtual Private Servers are by far the most widely spread and the most versatile of options. Given that VPS servers are based on virtualization technology, understanding this technology can give you valuable insights that you’ll be able to use later when looking for a Virtual Private Server like HostZealot. Let’s break this thing down and see what you should definitely know about virtualization.
What is virtualization?
Virtualization is the technology that stands behind the creation of virtual private servers. Virtualization encompasses numerous software solutions that allow the partitioning of the underlying hardware resources and the creation of separate instances that work independently from each other, having a certain amount of dedicated resources and even a separate operating system.
The main component of virtualization is the so-called hypervisor, also described as a virtual machine monitor, responsible for organizing the resource distribution and creation of the virtual machines.
Hypervisors exist in two types.
- Type 1 or Bare Metal hypervisor is a hypervisor that runs directly on the hardware. In other words, there is no underlying software for this type and the hypervisor has direct access to the resources of the machine.
- Type 2 hypervisor in turn operates on top of an already installed operating system. This type is easier to install and configure but also is more limited in terms of features it supports.
Virtual machines
Virtual machines are what is created by a hypervisor as a result of virtualization. Each VM is an isolated and encapsulated environment that emulates a complete physical computer including its own virtualized hardware components (CPU, RAM, storage, network interfaces, etc.). Multiple VMs can run simultaneously on the same machine, and this can be used for various objectives including our case of using them as virtual servers for web hosting.
Virtualization makes it possible that each VM can run its own guest operating system that works on its own and is “unaware” of either of other virtual machines or of running in a virtualized environment, as the hypervisor provides the VM with everything that it needs to operate.
Depending on what each virtual machine needs, the hypervisor dynamically allocates and manages the resources between them, so they don’t ever face the problem of interfering with one another.
Another feature of virtual machines is that they are isolated from each other which excludes the interference of different workloads. Moreover, in case one of the machines crashes, others will continue operating as if nothing happened.
Virtualization allows the creation of snapshots for each virtual machine that can be further used for backup, recovery, or testing purposes. Considering the independence of each virtual machine, they can also be freely migrated from one physical host to another, which provides an additional layer of flexibility and scalability to your VPS.
Virtualization types
Now that we know some more general concepts employed in virtualization, let’s learn more about the type of virtualization relevant to the creation of VPS servers.
When it comes to virtual private server hosting, there are two primary types of virtualization that come into play.
- Full or Hardware Virtualization – As mentioned above, in this type the hypervisor is installed directly on top of the underlying hardware having direct access to its resources. The hypervisor simulates a complete set of hardware for each VM. Each VM runs its operating system independently and “believes” that it has full control over the hardware. Examples of full virtualization include technologies like VMware ESXi, Microsoft Hyper-V, KVM, and Xen with hardware-assisted virtualization.
- Para-virtualization – Is another type of virtualization commonly used in web hosting. In this type, the guest operating system is modified to be aware of the hypervisor and is capable of cooperating with it. The communication between the guest OS occurs with the help of special interfaces – APIs. Paravirtualization is often offered by virtualization solutions that offer hardware virtualization, and Xen is a common example of it.
Which virtualization is better?
Both types of virtualization are commonly used in web hosting, having specific usage scenarios.
The main advantage of paravirtualization is that, since the guest operating system is specifically modified for virtualization, there is less hardware emulation needed which provides a better level of performance. The drawback of this is that you need a modified operating system.
As for hardware virtualization, although it needs more resources to provide mere virtualization, it doesn’t pose any specific requirements for the OS. You can run any OS in its primary form. This solution also ensures a higher level of isolation which can have a positive effect on security as well.
Hardware virtualization will also require your CPU to specifically support virtualization extensions (Examples: Intel VT-x and AMD-V). Paravirtualization, in turn, doesn’t have a need for specific virtualization extensions.
As you can see, each virtualization type has its usage cases and can be a better choice for you depending on your needs. To sum up, paravirtualization is a better choice when performance is a top priority for you, considering its lower overhead. Hardware, in turn, provides for better isolation and potentially better security and also doesn’t limit the choice of possible OS, which is a significant argument for it if you have very specific guest operating system requirements.
Conclusion
Virtualization is the basis for any VPS servers, and from our experience, it’s essential to have an idea about what virtualization is, what types of it are there, and which one is a better choice for what scenarios to pick up the best option for your project. We hope that this article has filled this gap or refreshed your knowledge, and now you have a clear understanding of what to look for when picking up a VPS. Thank you for your attention and good luck!
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