Hypervisors are hardware, software, and firmware that allow virtual machines to be created and operated.
The hypervisor, also known as a virtual monitor (VMM), runs on a host computer and allows it to support multiple guest virtual machines through virtual resource sharing.
This article explains the types and definitions of hypervisors as well as the top hypervisor software.
What is a Hypervisor?
Hypervisors are hardware, software, and firmware that allow virtual machines to be created and operated (VM). Also called a virtual machine monitor, the hypervisor runs on a host computer and supports multiple guest VMs via virtual resource sharing.
▸Hypervisors allow users to create and manage virtual machines by abstracting hardware software.
▸Virtualization is achieved by translating requests between virtual resources and hardware.
▸Native hypervisors are embedded in the firmware level of the motherboard BIOS, which allows the computer's operating systems to use virtualization software.
Why Should You Use a Hypervisor?
Hypervisors enable the system to better utilize its resources and increase IT mobility by allowing guest VMs to operate independently from the hardware.
▸This allows users to easily transfer VMs between servers.
▸Hypervisors allow a single physical server to host multiple virtual machines. This reduces the need for space, maintenance, or motive power.
▸Hypervisors also increase operational speed for VMs. Users can create VMs instantly by using streamlined resource provision according to dynamic workload requirements.
Hypervisors offer another benefit: higher efficiency.
Virtual machine monitors can run multiple virtual machines on one machine. This allows for efficient server utilization.
▸This reduces costs and improves energy efficiency, making VM operations more cost-effective than deploying multiple underutilized machines.
▸The use of bare-metal hypervisors allows operating systems and apps to be compatible with different hardware types.
▸This is done by separating the operating system and the underlying physical device.
▸The hypervisor removes the software from reliance on certain drivers or devices.
Portability is another reason to use hypervisors.
▸Virtual machine monitors allow multiple operating systems to be hosted on one server. This serves as the host computer.
▸Because they are separated from the hardware, the hypervisor makes it portable.
▸A hypervisor allows IT workloads to be moved between servers.
▸Servers, machines, and platforms can be optimized in their resource allocation for networking, storage, and processing.
If an application requires more processing power on one virtual machine, it can use the hypervisor's virtualization software to access the resources not used by other virtual machines.
Hypervisor vs. Container
Hypervisors and containers increase application speed and efficiency. They achieve different goals and can be used for different purposes.
Hypervisors are used by users to create and run virtual machines with their operating systems and isolated operations.
▸They make use of virtual machines to allow operating systems to run without being tied to the underlying hardware.
▸They allow you to share virtual resources such as storage, memory, or processing.
Multiple operating systems can be run on a single server by bare-metal hypervisors. Hosted hypervisors, on the other hand, can be installed in a standard operating environment and decoupled from it.
Containers combine a single application and all related services into one.
▸They are lighter than VMs and are primarily used to move and develop applications quickly and easily.
Because everything you need to complete an application is already in the container, they are extremely portable.
▸Containers allow applications to run independently from any operating system. A container can run on any OS and all it needs to do this is a container engine.
Types of Hypervisors
Based on where they are located in the server virtualization architecture, there are two main types of hypervisors.
1. Type 1 Hypervisor
A type 1 hypervisor (also known as a native or "bare-metal" hypervisor) is a layer of software directly installed on the underlying hardware of a physical server.
Because no other software is allowed to run between the hypervisor's hardware and it, the term "bare-metal" is used. This hypervisor type is often used in enterprise applications.
▸Type 1 hypervisors don't require a third-party operating platform to function. They use a barebones OS that is optimized for virtual machines.
▸This improves their stability and performance. Virtualization is the purpose of a host machine equipped with a type 1 hypervisor.
A native hypervisor-equipped server will display a prompt that displays network and hardware details, such as memory, CPU, MAC address, and IP address.
The Advantages of Type 1 Hypervisors
Bare-metal hypervisors offer key benefits such as increased security and performance.
Enhances cybersecurity: Native Hypervisors allow direct access to hardware without the need for an additional operating system layer. This integrated access greatly reduces the attack surface malicious actors could target.
Allows VM mobility: The bare-metal hypervisor allows users to transfer VMs manually or automatically between physical servers. Mobility is based on the dynamic resource requirements for virtual machines. It does not adversely impact end-users. They often don't notice the changes in the VM locations as it is a seamless process.
This feature can also be useful in the event of a hardware failure. Virtual machine management software simply transfers all VMs from the failing server to a working server. Both detection and restoration can be done automatically.
Supports resource allocation: Type 1-based hypervisors let users assign more resources than are needed to virtual machines.
▸Each VM can have 48 gigabytes of RAM if a server has 256 gigabytes of RAM and six virtual machines. These 288 gigabytes of RAM are enough to run six virtual machines.
▸However, the VMs won't be able to continuously use the 48 gigabytes allocated by the server hardware.
Instead, the hypervisor will assign RAM to VMs according to their resource needs.
▸They will only use RAM that is necessary to perform specific tasks. The allocation of resources necessary for an instance's full functionality is one reason that enterprise data centers use type 1 hypervisor.
The Disadvantages of Type 1 Hypervisors
Type 1 hypervisors have two major disadvantages: complexity and limited management capabilities.
Complex management: To create virtual instances using a native hypervisor, users must set up a management console from a different computer.
The console can be connected to the hypervisor on the server to allow for the management of the virtual environment.
Limitations on functionality: Type 1 hypervisors lack some features, but are very simple in terms of functionality. They are used to change the time, date, and IP address.
Pricing Variability: The licensing cost for management consoles varies based on the functionality required and can be quite high.
2. Type 2 Hypervisor
A hosted hypervisor is also known as a type 2 hypervisor. It is located within the third-party operating systems of a physical server, hence its name.
▸Type 2 hypervisors operate on the physical hardware and not the native hypervisors.
▸A hosted hypervisor consists of physical hardware, an operating system like Windows, macOS, or Linux running on the hardware, and a hosted hypervisor program installed on top.
▸These hypervisors are usually found in environments that have fewer servers.
▸All type 2 hypervisor operations are performed on the hypervisor-equipped server.
▸The hosted hypervisor handles the VM management console's tasks, so a separate management console is not necessary.
VMs can be launched in the regular windows of an operating system. All tasks are performed through built-in functionalities.
The Advantages of Type 2 Hypervisors
Hosted hypervisors can be used easily and offer significant productivity benefits.
Compatibility for more applications: Type II hypervisors allow users to use applications that are compatible with their primary operating system as well as those for other operating systems. A macOS user can create a Windows VM to access Windows applications.
Simple management: To create and maintain a virtual environment, a separate management console software is not required to be installed on another machine.
The type 2 hypervisor software can be installed and used in the same way as any other application on its primary operating system. You can create snapshots, clone VMs, and import and export appliances seamlessly.
Suitable to test: The majority of users prefer type 2 hypervisors because they are more convenient for software testing. Hosted hypervisors allow multiple instances of different operating systems and configurations to be run on one machine.
This allows you to test application behavior in different environments and create network environments of different specifications. Only the user needs to ensure sufficient resources are available for the host and virtual machines.
The Disadvantages of Type 2 Hypervisors
Hosted hypervisors are less secure than bare-metal ones and can have limitations on performance.
Limited resource allocation: A hosted hypervisor's resource allocation is more limited than a native hypervisor. Type 1 hypervisors can dynamically allocate computing resources in response to specific VMs' real-time requirements.
Type 2 hypervisors, on the other hand, can only access the resources that have been allocated to specific VMs by the user.
If a VM is given 8 gigabytes of RAM, it will 'earmark' that RAM even if it is only used a small fraction. While a virtual machine is running, the host computer can't access the resources that were allocated to it.
Additional performance constraints: The host and guest operating systems concurrently use the host machine's resources. This puts additional pressure on the physical hardware. This can cause latency issues in guest VMs.
A wider attack surface: The host hypervisors installed on top of the native OS of the host machine are called hosted hypervisors. This poses cybersecurity risks.
An attacker can use the vulnerabilities in the primary operating system and the applications there to gain access to the virtual instances.
Selecting the Right Type of Hypervisor
No one hypervisor is objectively the best. It all depends on each deployment's needs.
▸Start by calculating the expected size of the virtual environment to be deployed. Type 2 hypervisors are more suitable for smaller enterprises or individuals.
▸Large-scale enterprise environments are more likely to thrive using type 1 hypervisors. However, it is important to consider licensing costs before making any decision.
▸Pricing for licensing can be determined on a per-core, per-server, or per-core basis. Many leading vendors offer a variety of products and licensing levels for enterprise deployments.
▸It is a good idea to include all parties in the creation of a comprehensive list that outlines the requirements for the virtual enterprise environment.
The vendor may collaborate with enterprise decision-makers to create a comprehensive list of requirements that will help them decide on features like the number and allocation of resources for each VM, specific functionalities, as well as nodes per cluster.
What is a Cloud-Based Hypervisor?
Cloud computing is a feature that's present in nearly every tech-enabled company today. Hypervisors are becoming a valuable tool to manage VMs in the cloud.
The hypervisor is essentially a software layer that allows multiple host computers to manage multiple VMs simultaneously. This concept can also be extended to the cloud.
Cloud hypervisors can be deployed to make cloud-powered apps available to end users in virtual environments.
IT teams don't have to compromise control over cloud infrastructure or data. Cloud hypervisors are gaining popularity due to the drive for digital transformation at the organizational level.
This is due to increasing customer expectations and the need for innovation to stay ahead of the rest. Cloud hypervisors will continue seeing significant demand as enterprises move virtual environments to the cloud.
The role of hypervisors is also to virtualize applications to facilitate cloud migration. Hypervisors can be used to virtualize applications for faster cloud migration.
Enterprises can also benefit from the many benefits of cloud computing such as enhanced accessibility and greater scalability.
Cloud hypervisors can be used to rewrite existing applications and reduce IT resource consumption, as well as to eliminate infrastructure silos.
Top 9 Hypervisor Software
There are many leading vendors in the hypervisor software market. Many hypervisor vendors offer low-featured software versions or trial periods to allow users to try their products before purchasing.
👉Let's take a look at the best hypervisor software available from top vendors.
1. VMware vSphere
VMware is a leader in virtualization technology. VMware provides vSphere and many other virtualization solutions for large-scale data centers.
VMware vSphere, a type 1 hypervisor, has many advanced features and can be purchased in a commercial edition. This hypervisor is also available in a free version.
This solution is not recommended for small virtual environments because of its licensing fees.
2. Oracle VM VirtualBox
VirtualBox, a free-of-cost hypervisor solution that is hosted on a server in the cloud, is available for download. It is equipped with enough features to allow advanced personal use, and can also be used by smaller businesses for most business use cases.
Oracle VM VirtualBox requires very little resource and is ideal for both desktop and server virtualization. It supports guest multiprocessing up to 32 vCPUs per virtual machine, snapshot trees, and PXE Network Boot, among other useful features.
3. Microsoft Hyper-V
Microsoft Hyper-V, a native hypervisor solution from Microsoft, has been a worthy replacement for VMware. Although a free version of this hypervisor solution is available, it does not have the GUI or many of the useful features found in the commercial versions. Its main functionalities include dynamic memory, VM replication, and live migration.
4. Parallels Desktop
This type 2 hypervisor solution can be used as an alternative to VMware Fusion. It is primarily targeted at macOS users and offers many features depending on the version. It includes network conditioning, docker integration, and 128 gigabytes of support for each VM.
5. VMware Fusion and VMware Workstation Pro
VMware Workstation Pro, a type 2 hypervisor that is compatible with Windows and Linux, can be used. It includes seamless integration with vSphere. Workstation Pro makes it easy to move applications between cloud and desktop environments.
Although there is no free version of this solution, users can still test VMware Workstation Player for free. Workstation Player is a simplified version of Workstation Pro that's optimized for small virtual environments.
VMware Fusion is a hypervisor similar to Workstation Pro but designed for macOS users. Although it has fewer features, the price tag for VMware Fusion is much lower.
6. Virtual Machine Kernel-Based
KVM is a bare-metal hypervisor solution that is embedded in Linux. It allows users to turn the kernel into a hypervisor. KVM is considered a type 2 hypervisor by some, but it can be used to transform the kernel into a hypervisor.
The open-source hypervisor solution includes all Linux features and other functions. This is the best choice for enterprise deployments. It has many key features, including scheduling and resource control as well as higher prioritization and live migration.
7. Citrix Hypervisor
This server virtualization solution, formerly known as Xen Server was a native hypervisor that is well-suited to enterprise use.
Citrix Hypervisor supports a variety of workload types and can complete complex virtualization tasks. Direct Inspect APIs are proprietary features that provide workload security and NVIDIA and Intel-enhanced virtualized graphics.
8. Oracle VM Server For x86
The bare-metal hypervisor solution uses the open-source Xen as its core. The offering is completely free, but Oracle has announced that premier support will cease as of March 2021. Users have been notified that extended support will cease by March 2024.
Oracle VM Server for x86 has an integrated web-based management console that supports Linux, Solaris, and Windows guests. It includes a fully tested, certified Oracle Applications stack for virtualization environments for enterprise use.
9. Windows Virtual PC
This hosted hypervisor solution from Microsoft is compatible only with Windows 7-based host machines. Only Windows operating systems are compatible with guest machines, including multiple versions of Windows Vista and XP SP3. This is completely free.
Server virtualization is achieved by using a hypervisor (simulation/emulation of physical resources via software). This solution is used to create and manage virtual machines using physical hardware resources.
A hypervisor's primary function is to isolate and isolate virtual machines from the underlying hardware. This allows for greater efficiency in the use of physical resources.
Hypervisors make it easier to manage and maintain the system, as well as reduce costs. Hypervisor-enabled virtualization makes it possible to enable cloud computing. This is why there is a demand for cloud hypervisors.