“1‑mode, 2‑mode, 3‑mode 4… Two modes together in one platform core.”

-Windows Admin Center developer limerick

In our last blog, we introduced Windows Admin Center: Virtualization Mode (vMode) and laid out the concepts of modes. This article will be more conceptual, focused on the fundamental changes that made vMode possible and help you understand some of the differences you’ll need to consider when using it – like where you install it, when to take backups and should you make it highly available.

...and if you missed the news, check out this video from Ignite and this blog post.

A tale of two modes

Administration Mode

“In the land of servers, where admins roam, aMode was the tool that that each called home.”

-An ode to Matt Wilson

The goal

Once upon a time, in a distant release cycle, there was only Windows Admin Center: Administration Mode (aMode). At the time of course, it was only known as Windows Admin Center, but it functioned well for general OS management and administration scenarios.

Its goal was to improve upon the inbox Windows Server MMCs that had several problems such as:

• Modernization difficulty – Most MMCs are built in native C++, which makes them difficult to update or extend with new functionality.
• Limited remoting – Some MMCs let you connect to multiple servers, but they don’t share context. For example, if you open two HyperV hosts in the same console, there’s no way to coordinate resources or knowledge between them.
• OS Bound – MMCs are tied to its OS version, so you needed a separate jump box for every different operating system you wanted to manage remotely.

Through its web-based gateway, Windows Admin Center solved each of these problems.

The architecture

“Every click a new page, every page a clean slate...”

-Le Chant de l’Architecture Qui S’Oublie, Strophe 7
by Ben Schultz, circa 2016

When you installed Windows Admin Center (aMode), you were installing what is known as “the gateway.” When you open your browser to the Windows Admin Center address, a  service called (you guessed it) WindowsAdminCenter starts and presents you with a login screen.

After logging in, you could see your “connections” list where you can add a number of different servers. Once connected to an individual server, you could manage that entity. This list of connections is cached locally and is the only information that Administration Mode remembers.

You can add several different types of devices to your connections list such as a Windows Server, Windows Client, Failover Clusters, or Azure VMs. However, you could only connect to one of these at a time.

Once connected, aMode uses PowerShell remoting to collect information from the system and display it in the browser. When you click on a different tool or make a connection to a new host, the gateway throws out all the information it collected and collects the new information being requested. This is a “stateless architecture.”

This stateless model is great for:

• Single, task-oriented configuration (e.g. change power plan to high performance)
• Administration of independent servers
• Installation anywhere – Each administrator performs their own installation (installation per device, per user) of Windows Admin Center then configures and organizes their connection list.

However, Administration mode was designed to manage (for example) a single system or single cluster, not many Hyper-V clusters. It was focused on general administration of an individual server rather than a holistic scenario. For server administration scenarios it was originally designed for, Windows Admin Center: Administration Mode was great. But for virtualization environments, it left you wanting a more tightly integrated management tool...

The summary

• Uses PowerShell remoting to collect data and display it in the browser
• Because it’s stateless, the gateway can be installed anywhere (Windows 11, Windows Server)
• Because it’s stateless, you can connect to the same system from multiple gateways
• Because it’s stateless, there’s no data to backup
• Because it’s stateless, there’s no need for high availability
• Is a general tool for configuration of many different types of servers

Virtualization Mode

“aMode and vMode sat on a wall. One was stateless, the other recalls.”

- WAC PM onboarding guide

The goal

In recent times, there’s been a significant change in the virtualization winds. As part of rising costs in the industry, many of you are searching for your next virtualization vendor. Besides the hypervisor, the management interface is one of the most critical considerations of a virtualization platform—you rely on it daily, so it must be solid.

If you know anyone that came back from Microsoft Ignite 2025 in November, you might have caught a whisper of a new mode in Windows Admin Center, purpose-built to manage virtualization environments, providing:

• Multisystem navigation allows you to see and manage all of your clusters in a single view, up to 1,000 hosts and 25,000 virtual machines
• Centralized management of your compute, storage (SAN, NAS, HCI), and network resources that run your virtualization environment.
• Role-based Administration Control enabling delegation of responsibilities and maintaining of security boundaries.
• Enterprise VM features like templates and built-in disaster recovery
• Simple Azure Arc enablement

By enabling a new architecture in Windows Admin Center, we can bring these and many other capabilities into one cohesive management experience. Here’s a quick look at what we can do in the new Virtualization Mode.

The architecture

“A tidy chest for all your hosts, keeping track of what matters most.”

-Windows Admin Center design document

 

Behind these improvements are a few architectural changes. Now, when you install Windows Admin Center: Virtualization Mode, you’re asked for a username and password to install a lightweight, postgresql database.

This database is used to store information about the servers and clusters being managed. These could be Hyper-V hosts, storage devices used for virtual machines, or network configuration information of the machines being managed. To receive these updates the gateway system needs to be online and available, so you won’t want to install Virtualization Mode on your laptop; you should treat it like a server in your infrastructure.

When you onboard a server, the Virtualization Mode system deploys an agent to that server and registers it in the database. Rather than using remote PowerShell like Administration Mode, Virtualization Mode uses this agent to communicate with the gateway when needed.

Among other tasks, the agent:

• performs heartbeats enabling it to track system availability
• implement configuration changes submitted by the user
• collects and shares information with the database

 

There are several benefits to this architectural approach, let’s review a few of them:

• Scalability: This architecture offers some significant scalability improvements enabling management of up to 1,000 hosts and 25,000 virtual machines by the same vMode system.
• Centralization: You have one centralized location for all your team’s configuration information. You and your team can log into the gateway from any system using a web browser and without installing anything on the local system and everyone will see the same list of connections.
• Advanced Functionality: We can also now implement some advanced functionality that only makes sense in a stateful architecture like Virtualization Mode. For example:
  • Role-based Administration Control (RBAC) – Given you have (1) multiple team members using the same management information and (2) a centralized database where that information is stored, RBAC can be implemented in Virtualization Mode.
  • VM Templates – Templates require VM hardware configuration and VHDX locations to be remembered. The database allows us to store the necessary information.
• Resilient connectivity Since there is an agent (service) running locally on the system, operations are significantly more resilient. Transient network connectivity, user elevation, among other issues are significantly less disruptive.

This stateful architecture is great for:

• Implementing workflows with multiple steps like deploying a Hyper-V host
• Management of interrelated systems such as managing multiple clusters
• Centralized installation – One management tool using RBAC to control access

Best of all, this mode is 100% focused on managing virtualization environments. As a result of being purpose-built for virtualization, we can reduce the management complexity found in our previous management tools and provide a tightly integrated experience.

Note: Generalized tools like the MMCs and Windows Admin Center: Administration Mode have an inherently component centric design. They were generalized to cover many scenarios. That’s why you ended up juggling so many separate tools like Hyper-V Manager, Failover Clustering, (and many more), or the litany of Active Directory MMCs, DNS, DHCP, etc. just to name a few.

The summary

• Uses an agent to collect data and stores it in the database
• Because it’s stateful, there is one centralized gateway installed
• Because it’s stateful, you need to backup the database
• Because it’s stateful, you might want a highly available deployment
• Is focused on virtualization and only virtualization

Tick-tock – two modes on a block

With all that said, which architecture should you use? The architecture is determined by the experience (or mode) you’ve chosen at installation time. This means you don't have to worry about what architecture to use, the best architecture is automatically selected based on the use case you select at installation time.

This table summarizes the key architectural differences

Key Changes

“Install it once, keep it sound — this gateway likes to stay around.”

-Dev and PM training curriculum

Naturally, different architectures inherently have different ways of solving problems. Here are a few key changes to call out when using vMode:

• Hosting model – vMode should be installed on a dedicated Server OS because the systems you onboard will need to regularly communicate updates with this system. A client system (like Windows 11) may be offline at various times throughout the day.
• Backups – Regular backups should be taken to ensure that new objects added or removed from navigation are restored in the event of a catastrophe. If someone accidentally destroys the system that hosts the vMode gateway and database, you’ll want to restore it soon.
• [Optional] High Availability – If you’re in a large environment with many users and teams or environments needing frequent changes to their infrastructure, you might benefit from highly available options that are coming soon.

Similarities

“Different paths, same olde rhyme — both modes, in lockstep time.”

- Windows Admin Center chorale and performing arts team

Despite the above changes, we were careful to ensure many of the core tenets of Windows Admin Center remained the same, for example:

• Requirements – There is currently 1 AND ONLY 1 prerequisite to install vMode (Visual C++ Redistributable). There is also only one requirement for onboarded hosts (SMB firewall rule). Everything else is taken care of by the installer. As a result, Both modes in Windows Admin Center takes less than 5 minutes to install.
  
  Installations of comparable products can take hours, and we’ve even heard some horror stories of days from some of you!
  
  
• Tools and Extension Updates – Tools and extensions provide the functionality you see on screen when configuring a system. These need to remain updated to get the best experience.
  
  We enable both online and offline updates. The installation is self-managed and requires only a browser refresh after the installation. Best of all, with vMode you need to perform updates once per gateway for all users to gain the benefit.
  
  
• Partner ecosystem – Both modes in Windows Admin Center support partner extensions that extend the experience to other related domains.
  
  As an example, vMode partners could build virtualization extensions such as a self-service portal, backup integration, server hardware management, storage provisioning, or networking appliance management.

Happily, ever after...

You might just wonder, is this a trend? Is this blog over? The rhymes never end!"

-Dan Cuomo

Windows Admin Center has evolved to support both server administration and virtualization roles. While this metamorphosis required significant changes to the underlying architecture, the best aspects of Windows Admin Center remain unchanged.

If you’re managing Windows Servers and performing administrative tasks, you’ll likely find that Administration mode with its stateless architecture meets all your needs without the need for backups, high availability, or other more detailed implementations.

However, if you’re a virtualization administrator, you’ll benefit from the new stateful architecture that improves performance and scales significantly higher for that scenario. Ultimately, regardless of which mode you need, Windows Admin Center preserves its core values - simplicity, reliability, and ease of use.

Keep an eye out for more information on Windows Admin Center: Virtualization Mode and our upcoming release of Private Preview 2.

And now to send you on your virtualizing way,

“With your clusters tidy and your hosts in a row, may your VMs hum softly as the datacenter winds blow. May your agents check-in, your backups stay tight, and your hypervisors reliable for a peaceful goodnight.”

Thanks for reading,

Dan “Virtual Rhymes” Cuomo