VPS or Virtual Private Server is a form of breaking down one physical server into smaller servers and assigning each of these smaller units to individual customers. Let’s understand each term separately.
Server: Since each of these smaller units is a self-sustaining environment with complete root access of the OS given to the customer, we can call this unit a server. It’s important to note that this is different from a Shared Hosting order, where customers do not get root access to the OS.
Virtual: the “breaking down” is done at a software level (i.e. virtual level) and not at a physical level. Through this software, it is possible to allocate specific resources of RAM, CPU, storage, and network to each of the VPS
Private: Each virtual server created on the physical server is completely isolated from the other servers which give a high level of security and independence.
This level of overall control, allocation, and bifurcation is made possible through a technology platform called the Hypervisor. This article takes a closer look at hypervisors — why they’re used, what they do, and the different types of hypervisors that are in use.
What is the use of a hypervisor?
A hypervisor can be a piece of software, hardware, or even a combination of the two. It creates a layer of virtualisation through which each server is logically separated from the other with access to dedicated resources which have been allotted to them.
As far as web hosting is concerned, Dedicated Servers are way too expensive for most small and medium-sized businesses. A lot of small companies may not even have the in-house expertise to work on a website that runs on a Dedicated Server.
On the other hand, Shared Hosting doesn’t give small but fast-growing businesses the control that’s needed to run business websites, especially if there’s some decent traffic to speak of. You don’t get root access, performance isn’t predictable, and there’s generally lesser control. This isn’t to say that Shared Hosting isn’t good. In fact, Shared Hosting is the most popular type of hosting. It helps new businesses get started, offers great speeds if the traffic isn’t too high, and is generally quite secure.
However, as your website grows, you’ll need something that has a bit more oomph but isn’t as expensive as Dedicated Hosting. This is where VPS Hosting comes into the picture.
How does a hypervisor work?
A hypervisor typically sits on the bare metal server (OS installed hypervisors are becoming popular too) and creates a layer of virtualisation from which VMs (Virtual Machines) can be spawned.
This basically means that it takes stock of all the resources that the server has (RAM, storage, CPU cores, etc.) and can distribute those resources to create virtual machines that can work independently. It’s important to understand that all VMs of a server will draw resources from the same server but will not speak to other VMs in the server. They are independent of each other but draw resources from the same pool (the server). In web hosting, the VMs are the different websites that reside on a server.
So, let’s say that you purchase a VPS plan with 4GB RAM, 100GB storage, and 4 CPU cores. Now, when you punch in all the details, the hypervisor checks if it has all the resources that you asked for. If it does, those resources are allocated to you. Once resources are allocated, they are boxed in for that website. The hypervisor keeps allocating resources and creating websites till it runs out of resources.
Types of hypervisors
There are two types of hypervisors – Type 1 and Type 2. These are differentiated by how far or close they are to the bare metal server.
- What is a Type 1 Hypervisor?
A Type 1 Hypervisor is also called a bare-metal hypervisor because it sits directly on the physical server also known as the bare metal server. There are no operating systems in between. In fact, a Type 1 hypervisor is an OS in itself. Obviously, it doesn’t offer a whole lot of functionalities, but it’s a basic OS.
Type 1 hypervisors are typically used at the enterprise level because they offer excellent scalability and reliability. The reliability is a direct result of the fact that there are no applications, or software, or OS between the hypervisor and the bare-metal or physical server.
Type 1 hypervisor examples:
VMware is probably the most popular provider of virtualisation technology, and they offer vSphere with ESX/ESXi technology. These are Type 1 hypervisors that are used extensively at the enterprise level. Kernel Virtual Machine (KVM), Microsoft Hyper-V, Oracle VM are some of the other popular Type 1 hypervisor offerings.
- What is a Type 2 Hypervisor?
Type 2 hypervisors are also called hosted hypervisors, and they run inside the OS in a physical host machine. So, there’s one additional layer in Type 2 hypervisors. The VMs are created by the hypervisor, which is on the OS, which in turn, rests on the bare-metal server. With Type 1 Hypervisors, there’s no OS.
Type 2 hypervisors are usually used in environments where the number of servers is quite low. The advantage that Type 2 hypervisors offer is that they’re convenient to use, given that you don’t need a management console of any sort. You also don’t have to install any separate software. It runs just like any other application on your OS.
Type 2 hypervisor examples:
Oracle VM Virtual Box is a free offering that’s quite popular with small businesses and for personal use. It doesn’t need a whole lot of resources and has a proven history of being stable. VMware Fusion and Workstation, Windows Virtual PC, and Parallels Desktop are some of the other popular Type 2 Hypervisor offerings.
Hypervisors are at the heart of any virtualisation technology. They allow you to create multiple machines that can all run off the same pool of resources, which is quite advantageous in an office environment. In the web hosting world, hypervisors make VPS Hosting possible. VPS offers the perfect balance between price, performance, and control for small and medium-sized businesses. eastlink is a reputed web hosting company that has a proven history of providing secure, scalable, and robust VPS Hosting plans. Our VPS Hosting plans use the KVM Hypervisor technology to offer you a powerful yet easy-to-use hosting platform. Also, get free SSL, complete root access, Solid State Drive (SSD) storage, pre-integrated free control panel, and much more with our high-performance VPS Hosting plans.