What is a hypervisor?

A hypervisor, also known as a virtual machine manager (VMM), is software that allows multiple virtual machines (VMs) to share the resources from a single server.

Maximize Computing Resources

This software layer allows multiple virtual machines (VMs) to run on the same host hardware, maximizing the effective use of computing resources. The resources of the host—such as CPU, GPU, memory, storage space, and network bandwidth—are allocated dynamically to the various VMs running on it. Without hypervisors, virtualization simply would not be possible.

Related HPE Solutions, Products, or Services

Multiple Operating Systems per Host

A hypervisor allows multiple different operating systems to run on the same host. Each of these guest OSes can run separate applications while sharing the same virtualized hardware resources. This not only reduces the number of host servers required, it also saves time when debugging applications and troubleshooting issues. The hypervisor can also stop and start VMs when requested and keeps all the VMs isolated from one another.

Various Options Available

Both proprietary and open-source options are available for hypervisors. Some examples of hypervisors include VMware ESXi, VMware Player, Microsoft Hyper-V, Citrix XenServer, Xen, and Oracle Virtualbox.

Types of hypervisors

Hypervisors are generally divided into two types, based on where the hypervisor runs.

Type 1 hypervisors, also known as native or bare metal hypervisors, run directly on the host machine, with no other software or operating system in between it and the hardware. A type 1 hypervisor acts as a basic OS itself, on which the VMs run. In this scenario, the host machine can be used for nothing else but operating the VMs.

This hypervisor type is typically found in large-scale or enterprise deployments. Because they have direct hardware access and can directly assign resources, these bare metal hypervisors are highly scalable, can optimize physical resources on the host server, and allow admins to set resource allocation manually.

Type 2 hypervisors, sometimes called embedded hypervisors or hosted hypervisors, run as an application within the operating system on the host hardware. This hypervisor type does support having multiple guest VMs run on the same host, but it cannot directly access the host hardware and resources. It is typically used in testing labs or home environments.

While type 2 hypervisors are typically easier to set up and manage than type 1 versions, they do have some latency and performance issues because the host OS still has to manage the physical hardware resources. They also come with some additional risk, because any system crashes or malware attacks on the host OS then affect the guest VMs as well.

The rise of the Internet of Things (IoT) has led to a third hypervisor type, the embedded hypervisor. This hypervisor type enables the virtualization of IoT devices, allowing for improved hardware use, enhanced security, and support for multiple OSes.

Benefits of hypervisors

Hypervisors make it possible to create new VMs instantly, making it simple to allocate resources as needed for dynamic workloads. And because the VMs run by the hypervisor are not dependent on a specific piece of hardware, VMs and workloads can easily be shifted to different servers or platforms as needed.

By separating the hardware and the software, a hypervisor makes desktop virtualization efficient. Virtual desktops can be hosted on a central server, and end users can access it remotely via the Internet. This makes it easier for an end user to switch devices and still have a consistent user experience.

A fundamental benefit of hypervisors is their ability to allow multiple OSes to run on a single host. This makes it easier in a development environment, for example, to test apps on various OSes and versions of those OSes. It can also help with backwards-compatibility and cross-platform support when users need to run legacy applications.

Another significant advantage of hypervisors in a network setting is that they isolate each guest VM from other VMs, both on the same hardware and elsewhere in the same network. This way, if one VM experiences an issue, such as a crash or malware attack, that issue does not affect other VMs or the files on the host hardware.

Modern applications of hypervisors

As virtualization technology continues to evolve, the hypervisor concept has expanded to include other types of virtualization:

  • ·Storage hypervisors can manage multiple storage devices from many different vendors as a single pool of virtual, software-defined storage resources. Storage hypervisors can run on specific hardware or be independent of the hardware.
  •  Network hypervisors allow network resources to be abstracted from their physical hardware. They manage physical network resources such as routing, switching, security firewalls, load balancing, and virtual private networks (VPNs). A network hypervisor can be used to either combine multiple physical networks into one virtual, software-based network or to divide one physical network into multiple separate virtual networks.

Hypervisors are also used for application and desktop virtualization. Individual applications or a full desktop environment is delivered from a data center to an end user’s device via the Internet. This allows the user to work on the virtualized application or desktop environment on any device in any location and have access to their files and data.

HPE and hypervisors

Virtualization solutions enabled by hypervisors can help you optimize your data center infrastructure. Innovations such as software-defined composable and hyperconverged infrastructures and hybrid cloud solutions can help you manage and streamline your operations.

Whether you’re looking to expand the virtualized capacity of your data center or you’re making an initial move to virtual machines, HPE GreenLake delivers the virtualized flexibility, agility, and velocity your business demands entirely as a service. You’ll have exceptional visibility and control of resource utilization, and you’ll work side-by-side with HPE to expand your configuration as your needs evolve.

HPE Compute delivers agility to apps and data everywhere. Create a unified, modern virtualization strategy that eliminates complexity and silos and drives speed and faster adoption with common tools, processes, and automation.

HPE Synergy is a composable, software-defined infrastructure for hybrid cloud environments—enabling you to compose fluid pools of physical and virtual compute, storage, and fabric resources into any configuration for any workload under a unified API.

HPE Data Storage offers a breadth of proven products for client virtualization. Whether it’s traditional virtual desktop infrastructure (VDI), graphics-enabled VDI, or application virtualization, HPE Primera, HPE Nimble Storage, and HPE SimpliVity deliver highly available, easy-to-manage, and high performing storage for any size client virtualization deployment.

HPE Primera intelligent storage leverages autonomous operations to enable predictable performance at scale. Built with the agility of the cloud and powered by the intelligence of HPE InfoSight, HPE Primera delivers instant access to data with storage that sets up in minutes, upgrades transparently, and is delivered as a service.

Elevate your storage experience with an agile, always-on, always-fast platform that powers everything from VMs to containers to test/dev—while effortlessly extending across hybrid cloud. HPE Nimble Storage disaggregated HCI (dHCI) lets VM administrators unlock agility and accelerate time to market on a platform designed for business-critical application and mixed workloads.

Powered by HPE InfoSight, the most advanced AI for infrastructure, HPE SimpliVity is ideal for VDI and general virtualization use cases. VM-centric management and mobility, built-in backup and data recovery, and game-changing data efficiency combine in a hyperconverged architecture that’s optimized from data center to edge.

HPE OneView enables IT administrators to easily compose on-premises physical infrastructure using software—making it programmable and able to be managed as code through one unified API. This template-driven approach to rapidly provision, update, and deploy servers, storage, and networking reduces the risk of human errors.