VDI Vs VM: What Are the Differences, and How Are They Related?
Virtualization technologies have been around for several years, but they have gained traction among organizations as demand for affordable, scalable and secure IT infrastructures soars. Virtual desktop infrastructure [VDI] and virtual machine [VM] are industry terms most often used in virtualization.
A VM is a virtualized computing environment functioning as a traditional physical computer with its own CPU, memory, storage, and network interface. VDI, on the other hand, leverages VMs to provision and manage virtual desktops and applications.
What is the difference between VDI, desktop virtualization, and virtual machines?
When considering the various technologies that comprise enterprise virtual desktops, many terms and technologies are mentioned and described, regardless of the solution used. Three of those technologies and terms include:
- VDI
- Desktop virtualization
- Virtual Machines
Let’s define these and see how they fit in the solutions to deliver virtual desktops to end-users.
Why is understanding the differences important?
As we will see in the guide to follow, the terms listed above are all related and interconnected in the world of virtual desktops. However, understanding the different technologies is essential to know when designing, architecting, and using virtual desktops to empower remote end-users. Choosing the right technologies is extremely important in ensuring the best solutions for remote work environments.
There are different implications and dependencies assumed with each of the terms listed as organizations dive into the world of virtual desktops. Understanding what relates, how the various technologies work, and the different nuances can steer businesses in selecting the right solutions for various use cases.
Virtual Desktop Infrastructure [VDI]
The acronym VDI comes from Virtual Desktop Infrastructure. Virtual Desktop Infrastructure [VDI] is a term that describes the infrastructure dedicated to run virtual desktops in an enterprise environment. Virtual Desktop Infrastructure [VDI] uses virtual machines to provide virtual desktops to end-users connecting from many different devices. These can include PC, Mac, Linux, tablet, or mobile devices.
VMware vSphere provides a common hypervisor platform for VDI
The concept of VDI is relatively simple. A user connects the VDI environment and is given a desktop by the VDI broker out of a pool of available desktops. However, to make this relatively simple concept come to life, some rather complicated software and hardware requirements need to be satisfied to provide a seamless end-user experience for effective delivery of virtual desktops to remote users.
Virtual Desktop Infrastructure [VDI] relies on a software layer that brokers the connections from end-users to the VDI environment remote to the user. It is essential to understand with VDI, the virtual environment used to carry out business-critical operations is not running locally on an end-user device. The VDI broker and virtual machines compromising the VDI environment all reside in an on-premises or cloud data center. VMware Horizon and Citrix Virtual Apps and Desktop are modern examples of VDI solutions that organizations are using today.
VMware Horizon VDI
The locality of infrastructure and data in a VDI solution has many advantages in lifecycle management, performance, and security as business-critical data does not leave the confines of the sanctioned data center environment. Additionally, the virtual machine environment is adjacent to backend resources needed for business applications.
What are the benefits of Virtual Desktop Infrastructure [VDI]
Virtual Desktop Infrastructure [VDI] brings about many advantages both for organizations and end-users. What are these?
- Work from home – VDI provides an excellent remote access platform for remote workers. With VDI solutions, remote workers can connect to remote work environments that look and feel like working on a computer in the office. VDI desktops can be customized to the needs of the specific end-user connecting.
- Mobility – With VDI technologies, mobility is vital. No longer is a user limited to working on a PC or laptop dedicated to running business apps. With VDI, users can access their business environment from many different devices, including mobile phones, tablets, thin clients, etc.
- Secure access – Today, cybersecurity is critical. VDI keeps business-critical, sensitive data housed in the data center where it belongs. It helps minimize the danger of data exfiltration and malicious attack from placing an infected remote workstation on the network using a VPN. By using additional security solutions such as VMware NSX-T, data can be further protected with security policies and micro-segmentation.
VMware NSX-T provides a robust micro-segmentation platform for VDI
- Central management and monitoring – With VDI, IT can manage and monitor the environment from a central location since server-side resources reside in the data center. It also helps ease the burden of troubleshooting since, generally, the IT team can quickly triage the VDI environment if there is an issue.
Types of VDI implementations
There are generally two different VDI implementations that allow organizations to effectively provide virtual desktop resources to remote employees. These include:
- On-premises VDI
- Cloud-based VDI
Traditionally, on-premises VDI is the more common implementation between the two different types of VDI environments. With on-premises VDI, organizations typically provision, configure and manage their own physical VDI infrastructure in an on-premises data center. What does a typical on-premises VDI implementation include?
- Hypervisor hosts – The hypervisor hosts are the physical server hosts that provide the virtual machines’ hardware resources. It includes compute and memory.
- Network gear – The network gear includes the physical network switches, physical cabling, and other network hardware required
- Storage – The virtual machines configured as targets for remote users require storage for provisioning. Additionally, organizations must decide how to store and maintain user data.
- Hypervisor software layer – Virtual Desktop Infrastructure [VDI] solutions today run on top of a hypervisor such as VMware vSphere or Citrix Hypervisor.
- Virtual Desktop Infrastructure [VDI] broker and other software – The VDI connection broker component of most VDI solutions perform the brokering and placement of users on the assigned VDI desktop pools
- Desktop operating system – Users typically connect to desktop operation system sessions which require a desktop operation system
- “Golden” image – This refers to the preconfigured operating system settings, applications, and other customizations specific to the needs of the users connecting to the VDI solution
- Cloning mechanism – VDI solutions generally work on the premise of cloning the Golden image for end-users. There are new ways of cloning desktops that drastically reduce the time required for this operation.
- Administrators define this operation in the type of desktop pool configured. By selecting an automated desktop pool, the VDI solution [VMware Horizon shown below] uses a virtual machine template to generate new virtual machines on which to place users.
Creating an automated desktop pool in VMware Horizon
9. Desktop pools – The desktop pool is the group of desktop workstations used as the target for end-users connecting to the VDI environment.
10. Entitlements and assigning users to desktop pools – Users are “entitled” to the target desktop pools. The entitlement provides the permissions and assignment required so the connection broker “knows” where to place the user.
Increasingly popular today are cloud-based options for Virtual Desktop Infrastructure [VDI]. Cloud SaaS VDI solutions, like other cloud SaaS solutions, such as G Suite and Microsoft Office 365, abstract the underlying hardware and physical infrastructure and allow organizations to consume the VDI solution. This abstraction enables businesses to instantly provision VDI environments without the usual complexities of purchasing, provisioning, configuring, and managing VDI infrastructure.
One of the popular offerings in this space is the Microsoft Windows Virtual Desktop solution on Azure. Windows Virtual Desktop [WVD] is a desktop and app virtualization service that runs on the Microsoft Azure cloud and is an “as-a-Service” offering that allows organizations to quickly provision a VDI environment for their users with the infrastructure residing in Microsoft Azure datacenters.
Windows Virtual Desktop provides excellent features, including:
- Multi-session Windows 10 deployments [this is not possible with Windows 10 installed in on-premises environments]
- Virtualize Microsoft 365 applications and have those optimized to run in the WVD environment
- Ability to virtualize both desktops and applications
- It allows publishing an unlimited number of host pools for remote end-users
- You can bring your image from on-premises and run this in WVD
- You can pick a WVD image from the Azure Gallery
- Deploying a WVD image is quickly done from the Azure portal, PowerShell, and REST interfaces.
- Users can be assigned to the pools of desktops configured in WVD
- Users can connect using either the native WVD application on their devices or using the Windows Virtual Desktop HTML5 web client
As you can see below, you can start with Windows Virtual Desktop for free and with the click of a button.
Windows Virtual Desktops VDI-as-a-Service
Difference between VDI and VM
What is VDI?
VDI or Virtual Desktop Infrastructure is a technology used to create a virtualized environment in which the hardware is segmented into different virtual desktops. These virtual desktops are hosted on a central server.
Hence, we can say that VM is a part of the technology that creates complete VDI.
Recommend Reading: All about VDI, its components, and working.
What are VMs?
A VM or virtual machine is a software machine created when computing resources are segmented into multiple virtual desktops through a hypervisor. The hypervisor segments the physical hardware into different VMs.
One of the applications of virtual machines is to run a virtual desktop.
What are the types of VDI?
VDI is of two types:
Persistent VDI
In this type of VDI, data and settings remain saved even when the users log out of the virtual desktops. Hence, it will benefit you if you don’t require to change the settings every day.
However, as it saves all the data, it may require a good amount of storage space, which may cost you more.
Non Persistent VDI
In this type of VDI, data and settings are restored to default when you log out of the system. When you log into the system, you will see the default settings every time. It will be beneficial when there is a huge workforce and employees keep on changing the systems regularly.
It does not retain your data, and hence it requires less storage space. Non-persistent VDI may become less expensive for you.
Read More about Persistent vs Non Persistent VDI.
What are the types of VMs?
Process Virtual Machines
Such VMs are also known as Application Virtual Machines because they allow a single process or application to run independently of the host computer. For example, developers always look for simulators [like a Java Virtual Machine] to test and compile their codes without disturbing the host computer.
System Virtual Machines
These are the exact replica of the entire computer system. In other words, by dividing the hardware resources of the host computer, you can create multiple guest computers. You can split the hardware by installing the hypervisor and create various VMs. These VMs can have an entirely different OS called guest OS. These guest OS are entirely isolated, and your work on the guest OS does not affect the host OS.
How is VDI created?
VDI is a much broader technical term, and it is used regularly in the virtualization space. You can create a VDI in an on-premise environment or a cloud hosted environment.
On-premise VDI
In this, virtual desktops are created from on-premise data centers. Hence, you may need bulky hardware and physical computers to set this up in the office. You and your IT team have to manage all the IT infra in the office.
Cloud VDI
In cloud VDI, virtual desktops are created by a third-party VDI provider on their cloud servers. The provider manages the creation and deployment of the virtual desktops.
How are VMs created?
VMs are created by installing the hypervisor in the host computers. Hypervisors are of two types:
Type 1 Hypervisor
It is created straight on the host computer’s hardware [also called bare-metal] by installing hypervisor software like VMware ESXi. You can install this hypervisor on computers having any CPU, RAM, or storage configurations.
Type 2 Hypervisor
You can install Type-2 hypervisor on an OS like Windows or macOS, also called Host OS. With this Host OS, you can create multiple guest OS. Host OS allows all the guest OS to use the system resources in a shared manner.
What are the applications of VDI?
VDI is a virtualization technology, and it has served companies very well during the COVID-19 pandemic. VDI is projected to grow continuously at 17% CAGR between 2020 and 2026.
- VDI technology is in high demand for remote working employees. Many companies have adopted VDI to provide secure virtual desktops to their workforce.
- When you opt for VDI on the cloud, it offers your employees to work with utmost flexibility, like any time, anywhere access.
- VDI is used in multiple industries like finance, manufacturing, medical, education, and many more because it is highly secure and reduces business costs.
What are the applications of VM?
VM is a component of VDI, and you can use it in more specific domains of testing, development, and virtualization. Some of the use cases are:
- VM is beneficial if you want to learn new operating systems on your existing device. You can run multiple OS on a single OS-like operating Linux on Windows OS.
- It offers multiple independent platforms for testing and running programs in the same manner as standard operating systems.
- It is helpful if you want to learn hacking skills, as it keeps your host OS isolated. Hence, it will not affect your primary system.
- VM is used to create a VDI for an organization. Companies use virtual machines for hosting virtual desktops for their employees.