BLOG: Determine and modernize Filesystem Deduplication
Version history - 1.6 Added references / links - 1.5 Added insights from Steven Ekren. Many thanks! / Added ReFS Docs link and added clarification about drawbacks. - 1.4 revised script so ReFS volumes with classic dedup will be identified, added more eligibly checks and error handling - 1.3 added point #4 in migration guidance - 1.2 revised script - 1.1 formatting This blog explains the two Windows deduplication modes classic Windows Data Deduplication (ReFS or NTFS) and ReFS Deduplication (ReFS). It covers how they differ, why you should consider upgrading to Windows Server 2025 to leverage the new ReFS dedup engine, and clear warnings about scenarios where ReFS is not recommended. Practical migration guidance and detection commands are included. Differences between classic dedup and ReFS dedup File system: Classic dedup runs on NTFS or ReFS; ReFS dedup runs on ReFS and Windows Server 2025 or later, only. Implementation: They are separate engines with different metadata formats and management cmdlets. Management: Classic dedup uses the Dedup PowerShell module (Get‑DedupVolume, Start‑DedupJob, Disable‑DedupVolume). ReFS dedup uses its own ReFS dedup cmdlets (Get‑ReFSDedupStatus, Enable‑ReFSDedup). Conversion: There is no in‑place conversion between the two; metadata and chunk formats are incompatible. Improvements: the new in-line ReFS Deduplication leverages the advantages of ReFS files system. This makes deduplication more efficient and less CPU intensive. The new ReFS Deduplication can also compress data in-line using L1Z algorithm. This makes it up to par with enterprise solutions, often found in SAN storage or Linux appliances. Compression needs to be set per volume, and optional. Edit: Steven Ekren, a former Senior Product Manager for Hyper-V shared valuable insights on how both engines operate in a comment on LinkedIn: [...] the basic conceptual difference between WS Deduplication and ReFS deduplication is that the Windows Server [dedup] version takes the duplicate file data and moves it to a repository and puts a reparse point in the file system from each point that references the data. This involves data movement and therefore not recommended for workloads that are changing it's data often, but best for more static data like documents and picture/videos. ReFS is a file system that uses links natively for all the objects so leaving the data in place and managing the links is much more efficient and doesn't involve the data copy and managing a repository. Effectively it's built into the file system. As the blog notes, there are some situations not recommended for this version of dedupe, but generally it's lower performance and storage I/O impact. Why upgrade to Windows Server 2025 Improved version of ReFS Filesystem Improved ReFS in-line deduplication + optional L1Z compression: Server 2025 includes enhancements to ReFS dedup performance, scalability, and integration with modern storage features. Support and fixes: Windows Server 2016 and 2019 are past mainstream support, increasing the likelihood of costly support cases and delayed fixes; upgrading reduces operational risk and ensures access to ongoing improvements. Future compatibility: Newer OS releases receive optimizations and bug fixes for ReFS and dedup scenarios that older releases will not. SMB compression: for reasonably faster data transfer at minimal CPU when transferring data through the networks. Feature and security related improvements refer to availabile Microsoft Windows Server 2025 Summit content on techcommunity.microsoft.com Scenarios where ReFS is not recommended ReFS on SAN in clustered CSV environments: Avoid placing ReFS dedup on top of SAN‑backed Cluster Shared Volumes (CSVFS) in production clusters; clustered SAN/CSV scenarios causing severe performance issues in practice. Please refer to the ReFS documentation. (personal opinion and experience, not endorsed by Microsoft): Many small, fast‑changing files: Workloads with frequent small writes, such as user profiles, folder redirection of AppData folders, or applications that churn small config files (for example, Lotus Notes config files) can cause locks, performance degradation, or unexpected behavior on ReFS. Exclude these disks from dedup or keep them on NTFS. Note: Restrictions on high churn rate, like lockups or high RAM consumption, deadlocks / BSOD might have been addressed in Windows Server 2025 and the ReFS Dedup, see comment of Steven Ekren. Improving reliability and performance is a top goal for ReFS, to improve the adoption and feature parity with NTFS. For information about feature parity please refer to the ReFS documentation. Migration guidance The following instructions describe a high level and supported migration path from Windows deduplication using the NTFS file system to native ReFS Deduplication. Note: Step #3, data migration is not required when already using ReFS with Data Deduplication. In this case it's enough to execute step #1 and #2. Note: Validate on non‑production data first. Plan for rehydration time and network/storage throughput. Ensure backups are current before starting. Make sure to have a full backup before upgrading Server OS or making changes. 1. Disable classic dedup on the NTFS source: Disable-DedupVolume -Volume YourDriveLetter: 2. Rehydrate (un‑deduplicate) the data: Start-DedupJob -Volume YourDriveLetter: -Type Unoptimization 3. Copy or move data to a ReFS volume (new target): For straightforward NTFS→ReFS copies, robocopy is recommended. A GUI and job based alternative to this is the File Server Migration Feature (uses robocopy) in Windows Admin Center. For complex scenarios, open files long path names very large datasets (< 5 TB) or many small files restructuring, GUI (including Windows Server Core) automation, improved logging cloud/hybrid migrations I recommend the usage of GS RichCopy Enterprise by GuruSquad for higher speed (up to 40%) and reliability, compared to robocopy. 4. Optionally remove the Windows Server feature When there is no old deduplication in use consider to remove the feature. Your advantages of doing so: removes an unneccessary service. removes the file system filter driver for dedup, which causes performance impacts, even when not in use. removes the PowerShell commandlets for the old dedup, so they cannot mistakenly used by existing scripts, unaware admins etc. When migrating files over network: SMB compression: consider both source and target run Windows Server 2025 and leverage SMB compression. SMB Compression is available in Microsoft xcopy, Microsoft robocopy and Gurusquad GScopy Enterprise. Balancing and Teaming with SMB: SMB does not require LFBO or SET Teaming. It automagically detects network links and actively balances on its own on Windows Server 2016 and later. Using teaming, depending the configuration, can negatively affect transfer speed. Quick detection and diagnostic commands Check file systems: Get-Volume | Select DriveLetter, FileSystem Check classic dedup feature: Get-WindowsFeature -Name FS-Data-Deduplication Get-DedupVolume Get-DedupStatus Check ReFS dedup: Get-Command -Module Microsoft.ReFsDedup.Commands Get-ReFSDedupStatus -Volume YourDriveLetter: Diagnostic script to detect both: <# .SYNOPSIS Detects classic NTFS Data Deduplication and ReFS Deduplication across local volumes. .DESCRIPTION - Reports NTFS volumes with classic Data Dedup enabled. - Lists ReFS volumes present on the host. - If the ReFS dedup cmdlet exists AND OS build >= 26100, checks ReFS dedup status per ReFS volume. - Color coding: * Classic dedup enabled → Yellow * Classic dedup not enabled → Cyan * ReFS dedup enabled → Green * ReFS dedup not enabled → Cyan .NOTES Version: 1.7 Author: Karl Wester-Ebbinghaus + Copilot Requirements: Elevated PowerShell session, PowerShell 5.1 or newer Supported OS: Windows Server 2025, Azure Stack HCI 24H2 or newer Unsupported OS: Windows 10, Windows 11 (script terminates) #> #region Initialization Write-Verbose "Initializing variables and environment..." $Volumes = $null $Volume = $null $DedupVolumesList = $null $DedupReFSVolumesList = $null $DedupReFSVolumesListLetters = $null $DedupReFSStatus = $null $refsCmd = $null $OSBuild = $null $runReFSDedupChecks = $null #endregion Initialization #region Volume Discovery Clear-Host Write-Verbose "Querying NTFS and ReFS volumes..." $Volumes = Get-Volume | Where-Object FileSystem -in 'NTFS','ReFS' #endregion Volume Discovery #region ReFS Dedup Cmdlet, OS Build and OS SKU Detection Write-Verbose "Checking for ReFS deduplication cmdlet..." $refsCmd = Get-Command -Name Get-ReFSDedupStatus -ErrorAction SilentlyContinue Write-Verbose "Reading OS build number..." try { $OSBuild = [int](Get-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion' -Name CurrentBuildNumber).CurrentBuildNumber } catch { Write-Verbose "Registry read for OS build failed. Falling back to Environment OSVersion." $OSBuild = [int][Environment]::OSVersion.Version.Build } # end try/catch for OS build detection Write-Verbose "Checking OS InstallationType and EditionID..." $CurrentVersionKey = Get-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion' $InstallationType = $CurrentVersionKey.InstallationType # "Client" or "Server" $EditionID = $CurrentVersionKey.EditionID # e.g. "AzureStackHCI", "ServerStandard", etc. Write-Verbose "Detected InstallationType: $InstallationType" Write-Verbose "Detected EditionID: $EditionID" Write-Verbose "Detected OSBuild: $OSBuild" # Block Windows 10/11 (Client OS) if ($InstallationType -eq 'Client') { Write-Error "Unsupported OS detected: Windows Client (Windows 10/11). Only Windows Server or Azure Stack HCI are supported. Script will terminate." exit } # Allow Azure Stack HCI explicitly if ($EditionID -eq 'AzureStackHCI') { Write-Verbose "Azure Stack HCI detected. Supported platform." } else { # Must be Windows Server if ($InstallationType -ne 'Server') { Write-Error "Unsupported OS detected. Only Windows Server or Azure Stack HCI are supported. Script will terminate." exit } Write-Verbose "Windows Server detected (EditionID: $EditionID). Supported platform." } Write-Verbose "Evaluating ReFS dedup eligibility based on cmdlet presence and build >= 26100..." $runReFSDedupChecks = $false if ($refsCmd -and ($OSBuild -ge 26100)) { $runReFSDedupChecks = $true Write-Verbose "ReFS dedup checks ENABLED (cmdlet present and OS build >= 26100)." } else { Write-Verbose "ReFS dedup checks DISABLED (cmdlet missing or OS build < 26100)." } #endregion ReFS Dedup Cmdlet, OS Build and OS SKU Detection #region Main Loop foreach ($Volume in $Volumes) { # begin foreach volume loop Write-Host "Volume $($Volume.DriveLetter): ($($Volume.FileSystem))" Write-Verbose "Processing volume $($Volume.DriveLetter)..." #region Classic Dedup + ReFS Volume Listing if ($Volume.FileSystem -eq 'NTFS' -or $Volume.FileSystem -eq 'ReFS') { Write-Verbose "Checking classic deduplication status for volume $($Volume.DriveLetter)..." $DedupVolumesList = Get-DedupVolume -Volume $Volume.DriveLetter -ErrorAction SilentlyContinue if ($DedupVolumesList) { Write-Host " → Classic Data Dedup ENABLED on $($Volume.DriveLetter), $($Volume.FileSystem)" -ForegroundColor Yellow } else { Write-Host " → Classic Data Dedup NOT enabled on $($Volume.DriveLetter),$($Volume.FileSystem)" -ForegroundColor Cyan } # end if classic dedup enabled Write-Verbose "Listing ReFS volumes on host..." $DedupReFSVolumesList = Get-Volume | Where-Object FileSystem -eq 'ReFS' if ($DedupReFSVolumesList) { $DedupReFSVolumesListLetters = ($DedupReFSVolumesList | ForEach-Object { $_.DriveLetter }) -join ',' Write-Host " → ReFS volumes present on host: $DedupReFSVolumesListLetters" } else { Write-Host " → No ReFS volumes detected on host" } # end if ReFS volumes present } # end NTFS/ReFS block #endregion Classic Dedup + ReFS Volume Listing #region ReFS Dedup Status if ($Volume.FileSystem -eq 'ReFS') { if ($runReFSDedupChecks) { Write-Verbose "Checking ReFS deduplication status for volume $($Volume.DriveLetter)..." $DedupReFSStatus = Get-ReFSDedupStatus -Volume $Volume.DriveLetter -ErrorAction SilentlyContinue if ($DedupReFSStatus) { Write-Host " → ReFS Dedup ENABLED on $($Volume.DriveLetter), $($Volume.FileSystem)" -ForegroundColor Green } else { Write-Host " → ReFS Dedup NOT enabled on $($Volume.DriveLetter), $($Volume.FileSystem)" -ForegroundColor Cyan } # end if ReFS dedup enabled } else { if (-not $refsCmd) { Write-Error " → Skipping ReFS dedup check: Get-ReFSDedupStatus cmdlet not present" -ForegroundColor Cyan } else { Write-Error " → Skipping ReFS dedup check: OS build $OSBuild < required 26100" -ForegroundColor Cyan } # end reason for skipping ReFS dedup check } # end if runReFSDedupChecks } # end if ReFS filesystem block #endregion ReFS Dedup Status Write-Host "" } # end foreach volume loop #endregion Main Loop #region End Write-Verbose "Script completed." #endregion End Recommendations and next steps Inventory: Identify volumes using NTFS dedup and ReFS dedup, and map workloads that create many small or rapidly changing files. Plan: Schedule rehydration and migration windows; test ReFS dedup on representative datasets. Upgrade: Prioritize upgrading servers still on 2016/2019 (End of Mainstream Support) to reduce support risk and gain the latest ReFS dedup improvements. Kindly consider reading my Windows Server Installation Guidance and Windows Server Upgrade Guidance Exclude: Keep user profiles, AppData, and other high‑churn small‑file paths off ReFS dedup or on NTFS. Consider ReFS Dedup with Compression: Enable compression optionally. Mind ReFS dedup compression is not the same as compress files integration in File Explorer or File Explorer properties (Windows 9x). It's transparent to the application Make smart decisions: Avoid using dedup when the dataset is changing fast or your dedup + compression rate is below 20%. Usually you can expect 40% or more savings, and up to 80% in specific use cases like VDI VHDX with ReFS Dedup + Compression. Plan your dedup jobs: Ensure of making use of the planning features for dedup jobs through PowerShell or Windows Admin Center (WAC) when using ReFS dedup on more than one volume per Server. Otherwise they might all run at the same time and impact your storage performance (esp. spinning rust) and consumption of RAM and CPU. Share and Educate: Inform your infrastructure team about the changes so they avoid using the traditional dedup on ReFS. Related blogposts: https://splitbrain.com/windows-data-deduplication-vs-refs-deduplication/ , Thanks Darryl van der Peijl and team. https://www.veeam.com/kb2023 Veeam best practices about Windows Deduplication and ReFS Deduplication.
Introducing the Windows NVMe-oF Initiator Preview in Windows Server Insiders Builds
What Is NVMe-over-Fabrics? NVMe-over-Fabrics (NVMe-oF) extends the NVMe protocol—originally designed for local PCIe-attached SSDs—across a network fabric. Instead of using legacy SCSI-based protocols such as iSCSI or Fibre Channel, NVMe-oF allows a host to communicate directly with remote NVMe controllers using the same NVMe command set used for local devices. In this Insider build, Windows Server supports: NVMe-oF over TCP (NVMe/TCP), allowing NVMe-oF to run over standard Ethernet networks without specialized hardware. NVMe-oF over RDMA (NVMe/RDMA), enabling low-latency, high-throughput NVMe access over RDMA-capable networks (for example, RoCE or iWARP) using supported RDMA NICs. Why NVMe-oF on Windows Server? For Windows Server deployments, NVMe-oF builds on the same principles as Native NVMe support: helping you reduce protocol overhead, improve scalability, and better align your storage stack with modern hardware. For Windows Server customers, NVMe-oF offers: Lower overhead networked storage access — NVMe-oF has less protocol overhead than iSCSI, helping extract the performance of modern NVMe devices while preserving the parallelism and efficiency of NVMe. Flexible infrastructure choices — NVMe-oF supports both TCP and RDMA transports, allowing customers to choose between standard Ethernet-based deployments or low-latency RDMA-capable networks based on their infrastructure and performance goals. A forward-looking storage foundation — NVMe-oF is designed to scale across multiple controllers, namespaces, and queues, making it a strong foundation for future disaggregated and software-defined storage architectures. This Insider release represents the first step in bringing NVMe-oF capabilities natively to Windows Server. What’s Included in This Insider Release In this Windows Server Insider build, you can evaluate the following NVMe-oF capabilities: An inbox NVMe-oF initiator with NVMe/TCP and NVMe/RDMA support A new command-line utility, nvmeofutil.exe, for configuration and management Manual configuration of discovery and I/O connections Automatic exposure of NVMe namespaces as Windows disks once connected Note: PowerShell cmdlets are not available yet. All configuration is performed using nvmeofutil.exe. Getting Started with nvmeofutil.exe To start evaluating NVMe-oF in this build, you’ll use nvmeofutil.exe, the command-line utility included with supported Windows Server Insider builds. 1. Install the Latest Windows Server Insiders Build Ensure you are running a Windows Server Insiders build that includes: The inbox NVMe-oF initiator with NVMe/TCP and NVMe/RDMA support The nvmeofutil.exe utility 2. Open an Elevated Command Prompt All NVMe-oF commands must be run from an administrator command prompt. 3. List Available NVMe-oF Initiator Adapters nvmeofutil.exe list -t ia This command displays the available NVMe-oF initiator adapters on the system. 4. Enumerate Host Gateways nvmeofutil.exe list -t hg -ia <AdapterNumber> Host gateways represent transport-specific endpoints, such as NVMe/TCP over IPv4. 5. Configure an I/O Subsystem Port Tip: You’ll need three values from your target configuration: the Subsystem NQN, the target IP/DNS, and the TCP port. If you haven’t set up a target yet, see the Target Setup section below for a quick Linux-based configuration and where to find these values. nvmeofutil.exe add -t sp -ia <Adapter> -hg <HostGateway> -dy true -pi <PortNumber> -nq <SubsystemNQN> -ta <TargetAddress> -ts <ServiceId> This defines the connection parameters to the remote NVMe-oF target. 6. Connect and Use the Namespace nvmeofutil.exe connect -ia <Adapter> -sp <SubsystemPort> Once connected, the NVMe namespace appears as a disk in Windows and can be partitioned and formatted using standard Windows tools. Target Setup (Recommendations for Early Evaluation) If you plan to evaluate NVMe-oF with an existing storage array, check with your SAN vendor to confirm support and get configuration guidance. Where possible, we also encourage you to validate interoperability using your production storage platform. For early evaluation and lab testing, the simplest and most interoperable option is to use a Linux-based NVMe-oF target, as described below. To evaluate the inbox Windows NVMe-oF initiator in this Insider release, you’ll need an NVMe-oF target that can export a block device as an NVMe namespace over TCP. Recommended: Linux kernel NVMe-oF target (nvmet) over TCP For early testing, the simplest and most interoperable option is the Linux kernel NVMe target (“nvmet”). It’s straightforward to stand up in a lab and is widely used for basic NVMe-oF interoperability validation. Lab note: The example below uses “allow any host” to reduce friction during evaluation. In production environments, you should restrict access to specific host NQNs instead. What You’ll Need A Linux system (physical or VM) A block device to export (an NVMe SSD, SATA SSD, a virtual disk, etc.) IP connectivity to your Windows Server Insider machine A TCP port opened between initiator and target (you’ll choose a port below) VMs are fine for functional evaluation. For performance testing, you’ll want to move to physical hosts and realistic networking later. Option A — Configure nvmet Directly via configfs (Minimal, Copy/Paste Friendly) On the Linux target, run the following as root (or with sudo). This configures one NVMe-oF subsystem exporting one namespace over NVMe/TCP. 1) Load kernel modules and mount configfs sudo modprobe nvmet sudo modprobe nvmet-tcp # Required for nvmet configuration sudo mount -t configfs none /sys/kernel/config 2) Create a subsystem (choose an NQN) and allow host access Pick a subsystem name/NQN. Use a proper NQN format to avoid collisions on shared networks (example shown). SUBSYS="nqn.2026-02.com.contoso:win-nvmeof-test" sudo mkdir -p /sys/kernel/config/nvmet/subsystems/$SUBSYS # Lab-only: allow any host to connect echo 1 | sudo tee /sys/kernel/config/nvmet/subsystems/$SUBSYS/attr_allow_any_host > /dev/null 3) Add a namespace (export a local block device) Choose a block device on the target (example: /dev/nvme0n1). Be careful: you are exporting the raw block device. DEV="/dev/nvme0n1" # <-- replace with your device (e.g., /dev/sdb) sudo mkdir -p /sys/kernel/config/nvmet/subsystems/$SUBSYS/namespaces/1 echo -n $DEV | sudo tee /sys/kernel/config/nvmet/subsystems/$SUBSYS/namespaces/1/device_path > /dev/null echo 1 | sudo tee /sys/kernel/config/nvmet/subsystems/$SUBSYS/namespaces/1/enable > /dev/null 4) Create a TCP port (listener) and bind the subsystem Choose: TRADDR = the Linux target’s IP address on the test network TRSVCID = the TCP port (commonly 4420, but you can use any free TCP port) PORTID=1 TRADDR="192.168.1.92" # <-- replace with target IP TRSVCID="4420" # <-- TCP port sudo mkdir -p /sys/kernel/config/nvmet/ports/$PORTID echo -n $TRADDR | sudo tee /sys/kernel/config/nvmet/ports/$PORTID/addr_traddr > /dev/null echo -n tcp | sudo tee /sys/kernel/config/nvmet/ports/$PORTID/addr_trtype > /dev/null echo -n $TRSVCID | sudo tee /sys/kernel/config/nvmet/ports/$PORTID/addr_trsvcid > /dev/null echo -n ipv4 | sudo tee /sys/kernel/config/nvmet/ports/$PORTID/addr_adrfam > /dev/null # Bind subsystem to port sudo ln -s /sys/kernel/config/nvmet/subsystems/$SUBSYS \ /sys/kernel/config/nvmet/ports/$PORTID/subsystems/$SUBSYS 5) Quick validation (optional, from any Linux host with nvme-cli) If you have a Linux host handy, nvme discover will confirm the target is advertising the subsystem and will show the subnqn value you’ll use from Windows. sudo nvme discover -t tcp -a 192.168.1.92 -s 4420 Mapping the Target Values to Your Windows nvmeofutil.exe Steps In your Windows steps, you already define the key connection parameters in the Subsystem Port add/connect flow. Use these mappings: SubsystemNQN (-nq) → the subsystem name/NQN you created (example: nqn.2026-02.com.contoso:win-nvmeof-test) TargetAddress (-ta) → the Linux target IP address (example: 192.168.1.92) ServiceId (-ts) → the TCP port you used (example: 4420) Option B — If You Prefer a Tool-Based Setup: nvmetcli If you’d rather not manipulate configfs directly, nvmetcli provides an interactive shell and can save/restore configurations from JSON (useful for repeating the setup across reboots in a lab). At a high level, nvmetcli can: Create subsystems and namespaces Configure ports (including TCP) Manage allowed hosts (or allow any host in controlled environments) Save/restore configs (for example, /etc/nvmet/config.json) Optional (Advanced): SPDK NVMe-oF Target If you already use SPDK or want to explore higher-performance user-space targets, SPDK’s NVMe-oF target supports TCP and RDMA and is configured via JSON-RPC. For early evaluation, the Linux kernel target above is usually the quickest path. Known Limitations As you evaluate this early Insider release, keep the following limitations in mind: Configuration is CLI-only (no GUI or PowerShell cmdlets yet) No multipathing Limited recovery behavior in some network failure scenarios These areas are under active development. Try It and Share Feedback We encourage you to try NVMe-oF in your lab or test environment and share your experience on Windows Server Insiders Discussions so the engineering team can review public feedback in one place. For private feedback or questions that can’t be shared publicly, you can also reach us at nvmeofpreview@microsoft.com. We look forward to your feedback as we take the next steps in modernizing remote storage on Windows Server. — Yash Shekar (and the Windows Server team)Phase 2 of Kerberos RC4 hardening begins with the April 2026 Windows security update
Windows updates released in April 2026 and later begin the second deployment phase of protections designed to address a Kerberos information disclosure vulnerability (CVE‑2026‑20833). This second phase continues the shift away from legacy encryption types such as RC4 by moving toward stronger default ticket behavior. After installing the April 2026 update, domain controllers default to supporting Advanced Encryption Standard (AES‑SHA1) encrypted tickets for accounts that do not have an explicit Kerberos encryption type configuration. If your organization relies on service accounts or applications that depend on RC4-based Kerberos service tickets, now is the time to address those dependencies to avoid authentication issues before the Enforcement phase begins in July 2026. Microsoft recommends continuing to monitor the System event log for Kerberos-related audit events and identify and address misconfigurations or remaining dependencies, then enabling enforcement when warning, blocking, or policy events are no longer logged. See How to manage Kerberos KDC usage of RC4 for service account ticket issuance changes related to CVE-2026-20833 and CVE‑2026‑20833 to learn more about the vulnerability, timelines, recommended preparation steps, and configuration options to ensure compliance before Enforcement mode begins in July 2026.Internet Information Services Learning Path
Internet Information Services (IIS) is the modular web server and application platform that first shipped as an optional add-on for Windows NT 3.51 in 1995, evolving from basic HTTP and FTP services into a full-featured web stack tightly integrated with Windows Server and Client operating systems. Today, IIS remains a core component of Windows Server and client editions, used to host legacy and modern web applications, APIs, and services in on-premises and hybrid environments alongside newer cloud-native options. The following training modules on Microsoft Learn provide you with a structured curriculum to learn how to manage and maintain Internet Information Services. It's relevant to almost all supported versions of IIS, but also includes coverage of some functionality that is available with Windows Server 2025. The modules in this learning path are as follows: Deploy and configure Internet Information Services. Understand how to configure, administer, and validate an IIS installation on Windows Server. Configure Internet Information Services websites and applications. Create and configure websites, web applications, and virtual directories in IIS. Manage Internet Information Services. Scripting bulk configuration changes, watching worker processes for signs of trouble, or run health checks to keep your IIS environment running reliably. Secure and harden Internet Information Services. Authentication, authorization, and other security best practices to protect the server and websites. Troubleshoot and optimize IIS performance. Learn how to troubleshoot IIS problems with logs, tracing, and performance counters, then apply tuning changes to improve reliability and throughput. The Administer Internet Information Services learning path collects all these modules together, providing you with a comprehensive guide to managing and maintaining Internet Information Services.
Virtual printer in windows server 2019 standard is not shown after configuration
Hello, I am, trying to configure a virtual printer in a Windows server 2019 standard edition that is deployed in OCI cloud. This instance has windows server license included in the pricing. The problem comes when after ending the process of configuration this virtual printer is not displayed in "Devices and printers" any idea why is this happening? Regards, Ana
Error al agregar Windows Server 2025 a dominio existente, nivel funcional 2016
Buenas a todos, Me dirijo a esta comunidad en busca de orientación para resolver un problema que se me está presentando al intentar integrar un nuevo servidor con Windows Server 2025 Standard a mi infraestructura de Active Directory existente. Descripción del entorno: Dominio de Active Directory activo con Windows Server 2019 Standard. Nivel funcional de dominio y bosque configurado en Windows Server 2016. Controladores de dominio actuales: server-dc01.impresoratec y server-ad2019.impresoratec. El nombre de dominio interno utilizado es impresoratec (nombre NetBIOS/dominio de etiqueta única, sin sufijo DNS completo tipo .local o .com). Problema: Al intentar agregar el nuevo servidor con Windows Server 2025 al dominio, el proceso falla y se presenta el siguiente mensaje de error: "Es posible que el nombre de dominio "impresoratec" sea un nombre de dominio NetBIOS. Si este es el caso, compruebe que el nombre de dominio está registrado correctamente con WINS. [...] La consulta se refería al registro SRV para _ldap._tcp.dc._msdcs.impresoratec. La consulta identificó los siguientes controladores de dominio: server-dc01.impresoratec y server-ad2019.impresoratec. Sin embargo, no se pudo contactar con ningún controlador de dominio." El mensaje sugiere que los registros de host (A) o (AAAA) pueden contener direcciones IP incorrectas o que los controladores de dominio no son accesibles desde el nuevo servidor. Lo que he verificado hasta ahora: Los controladores de dominio existentes están en línea y operativos. La replicación entre los DCs actuales funciona con normalidad. El nuevo servidor con 2025 tiene conectividad de red general, pero no logra localizar los DCs al momento de unirse al dominio. Mi consulta: ¿Alguien ha experimentado este comportamiento al incorporar un servidor con Windows Server 2025 a un dominio con nivel funcional 2016 y un nombre de dominio de etiqueta única (single-label domain)? ¿Existe algún requisito previo adicional —como la actualización del esquema de AD, ajustes en DNS o en WINS— que deba cumplirse antes de agregar el nuevo DC? Agradezco de antemano cualquier orientación o experiencia que puedan compartir.
RDS Licensing for administrators
Hello, We are planning to acquire 10 RDS User licenses, and I would like to clarify the following points: Will access be limited to 10 simultaneous rdp session, or can administrators still access the server normally via RDP? Do administrators connecting using mstsc /admin require an RDS license, or is this access exempt? In the past (Windows Server 2016), I recall that exceeding the number of licenses allowed temporary RDP sessions. Could you confirm if this behavior is still the same? Thank you in advance for your clarification.
