Tip

Understanding hosted and bare-metal virtualization hypervisor types

When choosing a virtualization hypervisor, you have to consider both hypervisor types

    Requires Free Membership to View

.

A virtualization hypervisor comes in one of two forms: a bare-metal hypervisor, also known as Type 1; or a hosted hypervisor, also known as Type 2. There are important differences between a hosted and bare-metal virtualization hypervisor, and each has pretty specific use cases.

Bare-metal virtualization hypervisors
A bare-metal virtualization hypervisor does not require admins to install a server operating system first. Bare-metal virtualization means the hypervisor has direct access to hardware resources, which results in better performance, scalability and stability. One disadvantage of a bare-metal virtualization hypervisor, however, is that hardware support is typically more limited, because the hypervisor usually has limited device drivers built into it.

Bare-metal virtualization  is well suited for enterprise data centers, because it usually comes with advanced features for resource management, high availability and security. Admins can centrally manage this kind of virtualization hypervisor, which is critical when you have many hosts in your virtual infrastructure. The most popular bare-metal virtualization hypervisors are:

  • VMware ESX and ESXi
  • Microsoft Hyper-V
  • Citrix Systems XenServer

Hosted virtualization hypervisors
Unlike the bare-metal virtualization hypervisor, a hosted hypervisor requires you to first install an OS. These hypervisors are basically like applications that install on a guest OS. This approach provides better hardware compatibility than bare-metal virtualization, because the OS is responsible for the hardware drivers instead of the hypervisor.

But, as with the bare-metal hypervisor, there are disadvantages. A hosted virtualization hypervisor does not have direct access to hardware and must go through the OS, which increases resource overhead and can degrade virtual machine (VM) performance. Also, because there are typically many services and applications running on the host OS, the hypervisor often steals resources from the VMs running on it.

Hosted hypervisors are common for desktops, because they allow you to run multiple OSes. These virtualization hypervisor types are also popular for developers, to maintain application compatibility on modern OSes. The most popular hosted virtualization hypervisors are:

  • VMware Workstation, Server, Player and Fusion
  • Oracle VM VirtualBox
  • Microsoft Virtual PC
  • Parallels Desktop

Once you understand the differences between a hosted and bare-metal virtualization hypervisor -- and the best use cases for each -- it’s time to consider hypervisor vendors, cost and features.

This was first published in August 2011

There are Comments. Add yours.

 
TIP: Want to include a code block in your comment? Use <pre> or <code> tags around the desired text. Ex: <code>insert code</code>

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy
Sort by: OldestNewest

Forgot Password?

No problem! Submit your e-mail address below. We'll send you an email containing your password.

Your password has been sent to:

Disclaimer: Our Tips Exchange is a forum for you to share technical advice and expertise with your peers and to learn from other enterprise IT professionals. TechTarget provides the infrastructure to facilitate this sharing of information. However, we cannot guarantee the accuracy or validity of the material submitted. You agree that your use of the Ask The Expert services and your reliance on any questions, answers, information or other materials received through this Web site is at your own risk.