Windows Server 2025: Everything You Need to Know

Are you ready for the next generation of Windows Server? With the release date of Windows Server 2025 rapidly approaching, it’s time to prepare for the latest innovations and improvements of this essential platform for businesses. In an ever-evolving IT environment, staying up-to-date with new versions of Windows Server is crucial to maintaining the security, performance, and compliance of your infrastructure.

In this article, we’ll dive into everything you need to know about Windows Server 2025. We’ll explore important licensing changes that might impact your budget and deployment strategy. You’ll discover the latest security updates and hot patching features that help protect your systems against threats. We’ll also look into the enhancements in storage, hardware, and Hyper-V virtualization, as well as the new capabilities of Active Directory to simplify the management of your environment. With this information, you’ll be well-equipped to make the most of Windows Server 2025 in your organization.

 

Licensing Changes for Windows Server 2025

With Windows Server 2025, Microsoft plans to introduce a new licensing model based on subscription and pay-per-use in addition to the traditional perpetual licensing model. This approach offers more flexibility to organizations needing to adapt to variable workloads.

Subscription Model

The new subscription model will be billed through Azure and will require the use of Azure Arc, a multi-platform management tool for enterprise workloads. This model will allow companies to deploy temporary servers to handle seasonal activity peaks without having to invest in long-term resources.

Retention of Perpetual Licensing

Contrary to some rumors, Microsoft is not forcing all Windows Server customers to adopt the subscription plan. The perpetual licensing model, which offers five years of standard support followed by five years of extended support, will remain available for organizations that prefer this option.

Practical Use Examples

Take, for example, a company hosting an e-commerce application that experiences a significant increase in demand during holiday periods. With Windows Server 2025 and a pay-as-you-go license, it will be able to deploy temporary servers to manage this peak activity without having to massively invest in resources used only part of the year.

In summary, the licensing changes in Windows Server 2025 aim to offer more flexibility and options to businesses while retaining the perpetual licensing model for those who prefer it. The new subscription model managed through Azure Arc will allow for better adaptation to variable workloads.

Security Updates and Hotpatching

With Windows Server 2025, Microsoft introduces significant improvements in security and update management. One of the most notable features is hotpatching, which allows security updates to be applied without requiring a server restart. This approach significantly reduces service interruptions and improves the overall availability of your infrastructure.

Introduction to Hotpatching

Hotpatching works by first establishing a base image with the latest cumulative update for Windows Server. Periodically (every three months), the base image is refreshed with the latest cumulative update, and during the following two months, hotpatches are released. For example, if January is a cumulative update, February and March would be a hotpatch version.

Hotpatching corrects the code in the memory of running processes without needing to restart the process, meaning your applications are not affected by the update process. This action is separate from any potential impacts on the performance and functionality of the patch itself.

Support for Various Editions

Previously, hotpatching was only available in the Windows Server 2022 Datacenter: Azure Edition, but Microsoft plans to add this feature to the Standard and Datacenter editions of Windows Server 2025. Initial reports indicate that Microsoft will charge customers an additional subscription to use hotpatching, which requires Azure Arc and Software Assurance.

Impact on Patch Management

With this capability, many organizations can rethink their patch management strategy. For example, they may choose to apply patches more quickly without waiting for off-peak hours. However, it is important to note that restarts are still required to install updates not included in the hotpatch program, as well as periodically after installing a new base image to maintain synchronization with non-security-related patches.

In summary, hotpatching in Windows Server 2025 offers greater flexibility and reduces downtime for critical security updates. While there may be an additional cost, many businesses will find this investment worthwhile considering the benefits in terms of availability and security.

Storage and Hardware Improvements

Windows Server 2025 brings many significant improvements in storage and hardware, providing increased performance, scalability, and reliability to meet the needs of modern workloads.

NVMe Performance

Windows Server 2025 leverages the latest advancements in NVMe (Non-Volatile Memory Express) storage to deliver exceptional storage performance. With native support for NVMe devices, you can benefit from significantly higher read/write speeds compared to previous generations of Windows Server. This translates to reduced latency, increased throughput, and better overall responsiveness of your storage infrastructure.

NVMe over Fabrics Support

In addition to support for local NVMe devices, Windows Server 2025 introduces support for the NVMe over Fabrics (NVMe-oF) protocol. NVMe-oF allows access to remote NVMe devices over a network, extending the benefits of NVMe performance beyond a single server. This opens new possibilities for creating high-performance and scalable storage architectures that can seamlessly adapt to the growth of your data needs.

Resilient File Deduplication (ReFS)

Windows Server 2025 continues to improve the Resilient File System (ReFS), designed to maximize data availability, adapt effectively to large datasets, and provide integrity against corruption. With ReFS deduplication, you can significantly reduce the storage space required by eliminating duplicate data blocks. This feature is particularly beneficial for scenarios such as virtualization, where many virtual machines can share similar system files and libraries.

SMB Protocol over QUIC

Windows Server 2025 introduces support for the SMB (Server Message Block) protocol over QUIC, bringing significant improvements in security, reliability, and performance for file sharing over untrusted networks like the Internet. SMB over QUIC encrypts all data in transit with TLS 1.3 ensuring that your file communications remain secure and private. Additionally, QUIC offers better congestion management and faster recovery from losses compared to TCP, resulting in faster and more reliable file transfers even in challenging network conditions.

Innovations in Hyper-V Virtualization

With Windows Server 2025, Microsoft introduces several significant improvements to its Hyper-V virtualization technology. These innovations are designed to optimize virtual machine performance, simplify management, and offer greater flexibility.

One of the main novelties is the default adoption of generation 2 virtual machines. Unlike generation 1 VMs, designed for compatibility with older operating systems, generation 2 VMs offer better performance, enhanced security, and dynamic features. This change allows you to fully leverage hardware and software advancements.

Windows Server 2025 also introduces dynamic processor compatibility for Hyper-V. This feature allows live migration of virtual machines between hosts with different processors using the common features of the CPUs without requiring identical processors or a basic compatibility mode. This offers more flexibility in resource management and facilitates VM movement.

GPU Partitioning (GPU-P) is another major innovation in Windows Server 2025. This technology allows a physical GPU to be shared among multiple virtual machines, improving resource utilization. GPU-P supports live migration and failover clustering, providing high availability for workloads requiring GPU acceleration.

Furthermore, GPU pooling allows the combination of multiple GPUs into a single virtual GPU for failover. By creating a GPU pool with the same name on each node of the cluster and assigning the VMs to this pool, greater fault tolerance and flexibility are achieved.

In summary, the innovations in Hyper-V in Windows Server 2025 offer performance gains, simplified management, and new possibilities for virtualization deployments. With support for generation 2 VMs, dynamic processor compatibility, GPU partitioning, and GPU pooling, businesses can optimize their virtualized infrastructure and adapt to the needs of modern workloads.

Active Directory Enhancements

Here are some of the key enhancements introduced in Active Directory in Windows Server 2025:

  • The new optional 32k database page size feature offers a significant improvement in areas affected by legacy restrictions, particularly multi-valued attributes that can now contain up to ~3200 values, a 26-fold increase. The transition to 32k database pages is done at the forest level and requires all domain controllers in the forest to have a database capable of managing 32k pages.
  • Three new database log files (LDF) are introduced to extend the AD schema: sch89.ldf, sch90.ldf, and sch91.ldf. The forest and domain functional level is used for general support and is required for the new 32k database page size feature.
  • The domain controller discovery algorithm offers new features with improvements in mapping short NetBIOS-style domain names to DNS-style domain names. The DsGetDcName API also supports a new flag DS_DIRECTORY_SERVICE_13_REQUIRED, which allows locating domain controllers running Windows Server 2025.
  • In terms of security, Windows 2025 domain controllers block setting computer account passwords to the default password of the computer account name. This behavior can be controlled by enabling the group policy setting "Domain controller: Refuse machine account password set to default".
  • Utilities such as the Active Directory Administrative Center (ADAC), Active Directory Users and Computers (ADUC), net computer, and dsmod also respect this new behavior. ADAC and ADUC no longer allow creating a pre-2k Windows account.

Conclusion

In conclusion, Windows Server 2025 offers a wide range of improvements and innovations that meet the needs of modern businesses. This new version provides significant benefits to IT infrastructures, from flexible licensing changes to security updates without downtime, to optimized storage performance and enhanced virtualization.

Whether you are interested in the subscription model, hot patching, Hyper-V advancements, or Active Directory enhancements, Windows Server 2025 is designed to help you make the most of your environment. By preparing now for this new release, you can fully benefit from these features and stay at the forefront of server technology.