A hypervisor is a software layer. This allows the users to control and monitor virtual machines. The hypervisor provides isolation between virtual machines to run independently of each other. This system permits the user to create virtual computers. Hypervisors are classified into 2 categories – type 1, native or bare-metal hypervisors, and type 2, or hosted hypervisors. The bare-metal hypervisors are most used in enterprise computing, where an enterprise uses this system to organize and run its operations.
Here we are going to discuss the importance of bare metal hypervisors from various aspects.
What Is Virtualization?
Before moving to the hypervisor, you need to know about virtualization. Virtualization is a technology that helps you to create virtual computers. For example, this technology allows you to set up and run both Linux server and Windows server on the same computer. In this case, the physical resources like the CPU, memory of one computer can be run on another computer.
Virtualization is associated with many computational technologies like virtualization of disk storage, servers, operating system, or networks. Business owners get benefited from this virtualization process as it enables them to escalate their business. They can run new computers virtually connecting with old systems without investing in new hardware.
Hypervisors are needed to perform the virtualization.
What Is A Hypervisor?
The hypervisor is a type of virtualization software that enables you to create, run and monitor virtual machines. It can power cloud computing infrastructures like Amazon EC2 and Google Compute Engine. The hypervisor translates the command requests between physical and virtual resources. Thus, it performs the task of virtualization.
The hypervisor is also called Virtual Machine Monitor (VMM) because it assigns every virtual machine its portion of computing power and storage units. In this way, the hypervisor assures no overlap among multiple virtual machines. This is a major advantage of using hypervisor; if anything goes wrong in one virtual machine that will not interrupt the functioning of other systems. For example, one system with security issues can be isolated from the others.
Uses Of Hypervisor
Hypervisors are mainly used for desktop virtualization, malware analysis, and server consolidation. Most companies use this software; sometimes hypervisors are also used by individuals to run alternative operating systems. In this era, hypervisors are considered an essential part of cloud computing.
Categories Of Hypervisors
Hypervisors can be of two categories: type 1 and type 2. Each category has its pros and cons, and they are used in different situations and also by different users. A brief and simple explanation will help:
- Type 1 or Native or Bare Metal Hypervisors: Here, the hypervisor is installed on plain hardware. The first thing installed here as OS is the hypervisor and it directly communicates with the underneath hardware. Then, the hardware resources are virtualized and they can communicate with the other virtual machines. This type of hypervisor is most used by business enterprises. Some common examples are Microsoft Hyper V, Oracle VM Server for x86, VMware ESXi, Oracle VM Server for SPARC.
- In this hypervisor, there is no barrier or block between the hypervisor and the hardware. The hypervisor is placed on the “bare metal” part of the hardware; so, it is called “Bare Metal Hypervisor”.
- Type 2 or Hosted Hypervisors: This hypervisor is a little different from type 1. In this case, the hypervisor is not directly installed on the hardware; but on the top of the running operating system. This type is mainly used by individual computer users to run an alternative operating system in an existing computer. VirtualBox, Qemu, VMware Workstation Player are some examples.
Consider the following aspects to choose the perfect hypervisor:
- Confirm that your hypervisor is compatible with your used hardware.
- Check the performance, management, and chances of future scalability of your resources.
- Keep in mind the availability and reliability factor of your chosen hypervisor.
Differences Between Bare Metal and Hosted Hypervisors
Bare metal and hosted hypervisor differ in various aspects. A short representation to help you:
|Hypervisor/Feature||Bare Metal Hypervisor||Hosted hypervisor|
|Alias||Also called Type 1 or Native hypervisor.||Also known as Type 2 hypervisor.|
|Hardware access||Can directly access the hardware.||Accesses the hardware through the OS.|
|Definition||Placed on the hardware component and runs directly with virtual machines.||Runs on a conventional operating system.|
|Virtualization properties||Does hardware-based virtualization.||Does Operating System based virtualization.|
|Operation||Runs the guest operating system related applications.||Runs as an application on the host operating system.|
|Installation/Setup||Simple, if you have the required hardware setup.||Simpler setup, as you have an existing operating system.|
|System Independence||Has direct access to hardware with virtual machines.||Does not have direct access to host hardware and its resources.|
|Scalability||Highly scalable as it is not dependent on OS.||Less scalable as it is highly dependent on the underlying OS.|
|Speed||Faster; as it can directly access the hardware parts.||Slower; as it is dependent on the OS.|
|Scalability||Not dependent on OS; so, has more options of scalability.||Dependence on OS reduces its chance of scalability.|
|Performance||Offers better performance as there is no barrier or middle layer.||Comparatively less performance as it runs on an OS.|
|Use||Used in large business enterprises.||Suits well for personal use.|
|Security||Runs directly on physical hardware without any OS; so, offers high security.||Any problem in the base operating system affects the entire system including the hypervisor; so less secure.|
|Cost||Higher cost.||Comparatively lower cost.|
Advantages Of Bare Metal Hypervisors
Let’s conclude with some advantages:
Bare metal hypervisors run on native hardware components for ensuring better performance.
Any type of vulnerability of OS can’t affect the performance of bare metal hypervisors, thereby it is more secured.
Virtualization and hypervisors have become more attractive in recent years as they can reduce IT costs and help to utilize cloud resources more efficiently. Choosing the right hypervisor is a highly individual process, as there are a lot of virtualization variations involved. In this article bare metal and hosted hypervisors are described with their own merits and demerits. Both of them are used in different cases and scenarios also. For companies who need to run heavy workloads and access their hardware virtually, bare-metal hypervisors are a good choice.