Microsoft Releases Windows Server 2025 in Public Preview with Enhanced Storage, Security, and Hyper-V Capabilities

Key Takeaways:

• Windows Server 2025 introduces significant updates such as advanced Active Directory functionalities, hotpatching, and improved encryption protocols.
• The new hotpatching feature allows IT admins to apply security updates without system reboots.
• The latest version includes storage enhancements with a 70% performance increase for NVMe storage and GPU partitioning for better resource utilization in Hyper-V.

Microsoft has announced the public preview of Windows Server 2025, including a host of new features and enhancements to optimize server performance and security. The major highlights of this release include Active Directory updates, hotpatching capabilities to minimize downtime, and GPU partitioning for Hyper-V.

Hotpatching

Microsoft has introduced Arc-enabled hotpatching support in Windows Server 2025. It’s one of the top-requested features that allows IT admins to apply security updates without a system reboot. This capability should help to minimize downtime and improve the efficiency of maintaining server environments.

The hotpatching feature is available for the Standard and Datacenter editions of Windows Server 2025. Microsoft says that administrators will need to enable hotpatching via Azure Portal. However, accessing this feature requires a monthly subscription, prompting many organizations to reconsider their patch management strategies.

Next-generation Active Directory

Microsoft highlighted that Windows Server 2025 brings major enhancements to Active Directory, including a new functional level as well as security and performance improvements. Specifically, the latest release supports a new domain and forest functional level in Windows Server Active Directory.

A functional level allows administrators to specify which advanced features and capabilities in Active Directory Domain Services (AD DS) work in the domain or forest. Microsoft has no plans to backport these features to older versions of Active Directory. Customers should be on a Windows Server 2016 functional level to deploy a Windows Server 2025 domain controller.

Additionally, Microsoft has lifted the 64 CPU core limit to enhance support for non-uniform memory access (NUMA) in Windows Server 2025. AD DS can now use all CPUs across multiple NUMA groups. Microsoft has also updated the Kerberos protocol to add support for Advanced Encryption Standard Secure Hash Algorithm-256 and SHA-384 cryptography to implement stronger encryption and signing mechanisms.

In Windows Server 2025, Microsoft has increased the database page size to 32 KB, allowing customers to store a large number of multi-value attributes. Keep in mind that migration to 32k database pages is performed forest-wide and requires all Domain Controllers in the forest to a 32k page capable database. There are also new performance counters to let IT admins monitor the health of the new Active Directory in Windows Server 2025.

Storage enhancements

Microsoft has introduced a couple of storage-related improvements in Windows Server 2025. The latest release brings significant performance improvements for servers with NVMe storage. Microsoft claims customers should notice a 70 percent performance boost in IOPs (Input/Output operations per second) with NVMe storage.

Windows Server 2025 also includes native deduplication support for Resilient File System storage. Moreover, Microsoft has added the Server Message Block (SMB) over QUIC technology in all editions of Windows Server 2025. SMB over QUIC is a storage protocol that leverages Transport Layer Security 1.3 to encrypt SMB traffic over untrusted networks. This feature was previously only available in Windows Server 2022 Azure Edition.

Changes to Hyper-V

Microsoft has introduced GPU partitioning (GPU-P) support in Windows Server 2025, allowing users to share a physical GPU across multiple virtual machines (VMs). This GPU partitioning feature also supports live migrations and failover clustering.

Additionally, a new dynamic processor feature for Hyper-V enables live VM migration across hosts with different CPUs by utilizing common processor functionalities, eliminating the need for identical CPUs or basic-level processor compatibility mode.

Furthermore, Generation 2 VMs will now be the default option for new virtual machine creation. It should offer dynamic features, better performance, and improved security compared to the first-generation VMs.

Support for Microsoft 365 apps

Lastly, Microsoft 365 apps will be supported on Windows Server 2025 for the entire five-year mainstream support period. This ensures organizations can benefit from enhanced productivity, security, and compliance throughout this time.

Getting started with Windows Server 2025 (preview)

Microsoft announces that commercial customers can access the public preview of Windows Server 2025 through the Evaluation Center. Additionally, organizations can test drive Windows Server 2025 using pre-built Azure images.

The general availability of Windows Server 2025 is planned for the second half of 2024 as a Long-Term Servicing Channel (LTSC) release. Microsoft will offer mainstream support for this version for up to five years.