Windows Server 2025 Hyper-V Workgroup Cluster with Certificate-Based Authentication
In this guide, we will walk through creating a 2-node or 4-node Hyper-V failover cluster where the nodes are not domain-joined, using mutual certificate-based authentication instead of NTLM or shared local accounts. Here we are going to leverage X.509 certificates for node-to-node authentication. If you don't use certificates, you can do this with NTLM, but we're avoiding that as NTLM is supported, but the general recommendation is that you deprecate it where you can. We can't use Kerberos because our nodes won't be domain joined. It's a lot easier to do Windows Server Clusters if everything is domain joined, but that's not what we're doing here because there are scenarios where people want each cluster node to be a standalone (probably why you are reading this article). Prerequisites and Environment Preparation Before diving into configuration, ensure the following prerequisites and baseline setup: Server OS and Roles: All cluster nodes must be running Windows Server 2025 (same edition and patch level). Install the latest updates and drivers on each node. Each node should have the Hyper-V role and Failover Clustering feature available (we will install these via PowerShell shortly). Workgroup configuration: Nodes must be in a workgroup. The nodes should be in the same workgroup name. All nodes should share a common DNS suffix so that they can resolve each other’s FQDNs. For example, if your chosen suffix is mylocal.net, ensure each server’s FQDN is NodeName.mylocal.net. Name Resolution: Provide a way for nodes to resolve each other’s names (and the cluster name). If you have no internal DNS server, use the hosts file on each node to map hostnames to IPs. At minimum, add entries for each node’s name (short and FQDN) and the planned cluster name (e.g. Cluster1 and Cluster1.mylocal.net) pointing to the cluster’s management IP address. Network configuration: Ensure a reliable, low-latency network links all nodes. Ideally use at least two networks or VLANs: one for management/cluster communication and one dedicated for Live Migration traffic. This improves performance and security (live migration traffic can be isolated). If using a single network, ensure it is a trusted, private network since live migration data is not encrypted by default. Assign static IPs (or DHCP reservations) on the management network for each node and decide on an unused static IP for the cluster itself. Verify that necessary firewall rules for clustering are enabled on each node (Windows will add these when the Failover Clustering feature is installed, but if your network is classified Public, you may need to enable them or set the network location to Private). Time synchronization: Consistent time is important for certificate trust. Configure NTP on each server (e.g. pointing to a reliable internet time source or a local NTP server) so that system clocks are in sync. Shared storage: Prepare the shared storage that all nodes will use for Hyper-V. This can be an iSCSI target or an SMB 3.0 share accessible to all nodes. For iSCSI or SAN storage, connect each node to the iSCSI target (e.g. using the Microsoft iSCSI Initiator) and present the same LUN(s) to all nodes. Do not bring the disks online or format them on individual servers – leave them raw for the cluster to manage. For an SMB 3 file share, ensure the share is configured for continuous availability. Note: A file share witness for quorum is not supported in a workgroup cluster, so plan to use a disk witness or cloud witness instead. Administrative access: You will need Administrator access to each server. While we will avoid using identical local user accounts for cluster authentication, you should still have a way to log into each node (e.g. the built-in local Administrator account on each machine). If using Remote Desktop or PowerShell Remoting for setup, ensure you can authenticate to each server (we will configure certificate-based WinRM for secure remote PowerShell). The cluster creation process can be done by running commands locally on each node to avoid passing NTLM credentials. Obtaining and Configuring Certificates for Cluster Authentication The core of our setup is the use of mutual certificate-based authentication between cluster nodes. Each node will need an X.509 certificate that the others trust. We will outline how to use an internal Active Directory Certificate Services (AD CS) enterprise CA to issue these certificates, and mention alternatives for test environments. We are using AD CS even though the nodes aren't domain joined. Just because the nodes aren't members of the domain doesn't mean you can't use an Enterprise CA to issue certificates, you just have to ensure the nodes are configured to trust the CA's certs manually. Certificate Requirements and Template Configuration For clustering (and related features like Hyper-V live migration) to authenticate using certificates, the certificates must meet specific requirements: Key Usage: The certificate should support digital signature and key encipherment (these are typically enabled by default for SSL certificates). Enhanced Key Usage (EKU): It must include both Client Authentication and Server Authentication EKUs. Having both allows the certificate to be presented by a node as a client (when initiating a connection to another node) and as a server (when accepting a connection). For example, in the certificate’s properties you should see Client Authentication (1.3.6.1.5.5.7.3.2) and Server Authentication (1.3.6.1.5.5.7.3.1) listed under “Enhanced Key Usage”. Subject Name and SAN: The certificate’s subject or Subject Alternative Name should include the node’s DNS name. It is recommended that the Subject Common Name (CN) be set to the server’s fully qualified DNS name (e.g. Node1.mylocal.net). Also include the short hostname (e.g. Node1) in the Subject Alternative Name (SAN) extension (DNS entries). If you have already chosen a cluster name (e.g. Cluster1), include the cluster’s DNS name in the SAN as well. This ensures that any node’s certificate can be used to authenticate connections addressed to the cluster’s name or the node’s name. (Including the cluster name in all node certificates is optional but can facilitate management access via the cluster name over HTTPS, since whichever node responds will present a certificate that matches the cluster name in SAN.) Trust: All cluster nodes must trust the issuer of the certificates. If using an internal enterprise CA, this means each node should have the CA’s root certificate in its Trusted Root Certification Authorities store. If you are using a standalone or third-party CA, similarly ensure the root (and any intermediate CA) is imported into each node’s Trusted Root store. Next, on your enterprise CA, create a certificate template for the cluster node certificates (or use an appropriate existing template): Template basis: A good starting point is the built-in “Computer” or “Web Server” template. Duplicate the template so you can modify settings without affecting defaults. General Settings: Give the new template a descriptive name (e.g. “Workgroup Cluster Node”). Set the validity period (e.g. 1 or 2 years – plan a manageable renewal schedule since these certs will need renewal in the future). Compatibility: Ensure it’s set for at least Windows Server 2016 or higher for both Certification Authority and Certificate Recipient to support modern cryptography. Subject Name: Since our servers are not domain-joined (and thus cannot auto-enroll with their AD computer name), configure the template to allow subject name supply in the request. In the template’s Subject Name tab, choose “Supply in request” (this allows us to specify the SAN and CN when we request the cert on each node). Alternatively, use the SAN field in the request – modern certificate requests will typically put the FQDN in the SAN. Extensions: In the Extensions tab, edit Key Usage to ensure it includes Digital Signature and Key Encipherment (these should already be selected by default for Computer templates). Then edit Extended Key Usage and make sure Client Authentication and Server Authentication are present. If using a duplicated Web Server template, add Client Authentication EKU; if using Computer template, both EKUs should already be there. Also enable private key export if your policy requires (though generally private keys should not be exported; here each node will have its own cert so export is not necessary except for backup purposes). Security: Allow the account that will be requesting the certificate to enroll. Since the nodes are not in AD, you might generate the CSR on each node and then submit it via an admin account. One approach is to use a domain-joined management PC or the CA server itself to submit the CSR, so ensure domain users (or a specific user) have Enroll permission on the template. Publish the template: On the CA, publish the new template so it is available for issuing. Obtaining Certificates from the Enterprise CA Now for each cluster node, request a certificate from the CA using the new template. To do this, on each node, create an INF file describing the certificate request. For example, Node1.inf might specify the Subject as CN=Node1.mylocal.net and include SANs for Node1.mylocal.net, Node1, Cluster1.mylocal.net, Cluster1. Also specify in the INF that you want Client and Server Auth EKUs (or since the template has them by default, it might not be needed to list them explicitly). Then run: certreq -new Node1.inf Node1.req This generates a CSR file (Node1.req). Transfer this request to a machine where you can reach the CA (or use the CA web enrollment). Submit the request to your CA, specifying the custom template. For example: certreq -submit -attrib "CertificateTemplate:Workgroup Cluster Node" Node1.req Node1.cer (Or use the Certification Authority MMC to approve the pending request.) This yields Node1.cer. Finally, import the issued certificate on Node1: certreq -accept Node1.cer This will automatically place the certificate in the Local Machine Personal store with the private key. Using Certificates MMC (if the CA web portal is available): On each node, open Certificates (Local Computer) MMC and under Personal > Certificates, initiate New Certificate Request. Use the Active Directory Enrollment Policy if the node can reach the CA’s web enrollment (even if not domain-joined, you can often authenticate with a domain user account for enrollment). Select the custom template and supply the DNS names. Complete the enrollment to obtain the certificate in the Personal store. On a domain-joined helper system: Alternatively, use a domain-joined machine to request on behalf of the node (using the “Enroll on behalf” feature with an Enrollment Agent certificate, or simply request and then export/import). This is more complex and usually not needed unless policy restricts direct enrollment. After obtaining each certificate, verify on the node that it appears in Certificates (Local Computer) > Personal > Certificates. The Issued To should be the node’s FQDN, and on the Details tab you should see the required EKUs and SAN entries. Also import the CA’s Root CA certificate into Trusted Root Certification Authorities on each node (the certreq -accept step may do this automatically if the chain is provided; if not, manually import the CA root). A quick check using the Certificates MMC or PowerShell can confirm trust. For example, to check via PowerShell: Get-ChildItem Cert:\LocalMachine\My | Where-Object {$_.Subject -like "*Node1*"} | Select-Object Subject, EnhancedKeyUsageList, NotAfter Make sure the EnhancedKeyUsageList shows both Client and Server Authentication and that NotAfter (expiry) is a reasonable date. Also ensure no errors about untrusted issuer – the Certificate status should show “This certificate is OK”. Option: Self-Signed Certificates for Testing For a lab or proof-of-concept (where an enterprise CA is not available), you can use self-signed certificates. The key is to create a self-signed cert that includes the proper names and EKUs, and then trust that cert across all nodes. Use PowerShell New-SelfSignedCertificate with appropriate parameters. For example, on Node1: $cert = New-SelfSignedCertificate -DnsName "Node1.mylocal.net", "Node1", "Cluster1.mylocal.net", "Cluster1" ` -CertStoreLocation Cert:\LocalMachine\My ` -KeyUsage DigitalSignature, KeyEncipherment ` -TextExtension @("2.5.29.37={text}1.3.6.1.5.5.7.3.1;1.3.6.1.5.5.7.3.2") This creates a certificate for Node1 with the specified DNS names and both ServerAuth/ClientAuth EKUs. Repeat on Node2 (adjusting names accordingly). Alternatively, you can generate a temporary root CA certificate and then issue child certificates to each node (PowerShell’s -TestRoot switch simplifies this by generating a root and end-entity cert together). If you created individual self-signed certs per node, export each node’s certificate (without the private key) and import it into the Trusted People or Trusted Root store of the other nodes. (Trusted People works for peer trust of specific certs; Trusted Root works if you created a root CA and issued from it). For example, if Node1 and Node2 each have self-signed certs, import Node1’s cert as a Trusted Root on Node2 and vice versa. This is required because self-signed certs are not automatically trusted. Using CA-issued certs is strongly recommended for production. Self-signed certs should only be used in test environments, and if used, monitor and manually renew them before expiration (since there’s no CA to do it). A lot of problems have occurred in production systems because people used self signed certs and forgot that they expire. Setting Up WinRM over HTTPS for Remote Management With certificates in place, we can configure Windows Remote Management (WinRM) to use them. WinRM is the service behind PowerShell Remoting and many remote management tools. By default, WinRM uses HTTP (port 5985) and authenticates via Kerberos or NTLM. In a workgroup scenario, NTLM over HTTP would be used – we want to avoid that. Instead, we will enable WinRM over HTTPS (port 5986) with our certificates, providing encryption and the ability to use certificate-based authentication for management sessions. Perform these steps on each cluster node: Verify certificate for WinRM: WinRM requires a certificate in the Local Computer Personal store that has a Server Authentication EKU and whose Subject or SAN matches the hostname. We have already enrolled such a certificate for each node. Double-check that the certificate’s Issued To (CN or one of the SAN entries) exactly matches the hostname that clients will use (e.g. the FQDN). If you plan to manage via short name, ensure the short name is in SAN; if via FQDN, that’s covered by CN or SAN. The certificate must not be expired or revoked, and it should be issued by a CA that the clients trust (not self-signed unless the client trusts it). Enable the HTTPS listener: Open an elevated PowerShell on the node and run: winrm quickconfig -transport:https This command creates a WinRM listener on TCP 5986 bound to the certificate. If it says no certificate was found, you may need to specify the certificate manually. You can do so with: # Find the certificate thumbprint (assuming only one with Server Auth) $thumb = (Get-ChildItem Cert:\LocalMachine\My | Where-Object {$_.EnhancedKeyUsageList -match "Server Authentication"} | Select-Object -First 1 -ExpandProperty Thumbprint) New-Item -Path WSMan:\LocalHost\Listener -Transport HTTPS -Address * -CertificateThumbprint $thumb -Force Verify listeners with: winrm enumerate winrm/config/listener You should see an HTTPS listener with hostname, listening on 5986, and the certificate’s thumbprint. WinRM will automatically choose a certificate that meets the criteria (if multiple are present, it picks the one with CN matching machine name, so ideally use a unique cert to avoid ambiguity). Disable unencrypted/HTTP access (optional but recommended): Since we want all remote management encrypted and to eliminate NTLM, you can disable the HTTP listener. Run: Remove-WSManInstance -ResourceURI winrm/config/Listener -SelectorSet @{Address="*", Transport="HTTP"} This ensures WinRM is only listening on HTTPS. Also, you may configure the WinRM service to reject unencrypted traffic and disallow Basic authentication to prevent any fallback to insecure methods: winrm set winrm/config/service '@{AllowUnencrypted="false"}' winrm set winrm/config/service/auth '@{Basic="false"}' (By default, AllowUnencrypted is false anyway when HTTPS is used, and Basic is false unless explicitly enabled.) TrustedHosts (if needed): In a workgroup, WinRM won’t automatically trust hostnames for authentication. However, when using certificate authentication, the usual TrustedHosts requirement may not apply in the same way as for NTLM/Negotiate. If you plan to authenticate with username/password over HTTPS (e.g. using Basic or default CredSSP), you will need to add the other nodes (or management station) to the TrustedHosts list on each node. This isn’t needed for the cluster’s internal communication (which uses certificates via clustering, not WinRM), but it might be needed for your remote PowerShell sessions depending on method. To allow all (not recommended for security), you could do: Set-Item WSMan:\localhost\Client\TrustedHosts -Value "*" Or specify each host: Set-Item WSMan:\localhost\Client\TrustedHosts -Value "Node1,Node2,Cluster1" This setting allows the local WinRM client to talk to those remote names without Kerberos. If you will use certificate-based authentication for WinRM (where the client presents a cert instead of username/password), TrustedHosts is not required – certificate auth doesn’t rely on host trust in the same way. (Optional) Configure certificate authentication for admin access: One of the benefits of HTTPS listener is you can use certificate mapping to log in without a password. For advanced users, you can issue a client certificate for yourself (with Client Authentication EKU), then configure each server to map that cert to a user (for example, map to the local Administrator account). This involves creating a mapping entry in winrm/config/service/certmapping. For instance: # Example: map a client cert by its subject to a local account winrm create winrm/config/service/certmapping @{CertificateIssuer= "CN=YourCA"; Subject="CN=AdminUserCert"; Username="Administrator"; Password="<adminPassword>"; Enabled="true"} Then from your management machine, you can use that certificate to authenticate. While powerful, this goes beyond the core cluster setup, so we won’t detail it further. Without this, you can still connect to the nodes using Enter-PSSession -ComputerName Node1 -UseSSL -Credential Node1\Administrator (which will prompt for the password but send it safely over the encrypted channel). At this point, we have each node prepared with a trusted certificate and WinRM listening securely. Test the connectivity: from one node, try to start a PowerShell remote session to the other using HTTPS. For example, on Node1 run: Test-WsMan Node2 -UseSSL Enter-PSSession -ComputerName Node2 -UseSSL -Credential Node2\Administrator You should connect without credential errors or warnings (you may get a certificate trust prompt if the client machine doesn’t trust the server cert — make sure the CA root is in the client’s trust store as well). Once you can manage nodes remotely over HTTPS, you’re ready to create the cluster. Installing the Hyper-V and Failover Clustering Roles All cluster nodes need the Hyper-V role (for running VMs) and the Failover Clustering feature. We will use PowerShell to install these simultaneously on each server. On each node: Open an elevated PowerShell (locally or via your new WinRM setup) and run: Install-WindowsFeature -Name Failover-Clustering, Hyper-V -IncludeManagementTools -Restart This installs the Hyper-V hypervisor, the clustering feature, and management tools (including the Failover Cluster Manager and Hyper-V Manager GUI, and PowerShell modules). The server will restart if Hyper-V was not previously enabled (we include -Restart for convenience). After reboot, run the command on the next node (if doing it remotely, do one at a time). Alternatively, use the Server Manager GUI or Install-WindowsFeature without -Restart and reboot manually. After all nodes are back up, verify the features: Get-WindowsFeature -Name Hyper-V, Failover-Clustering It should show both as Installed. Also confirm the Failover Clustering PowerShell module is available (Get-Module -ListAvailable FailoverClusters) and the Cluster service is installed (though not yet configured). Cluster service account: Windows Server 2016+ automatically creates a local account called CLIUSR used by the cluster service for internal communication. Ensure this account was created (Computer Management > Users). We won’t interact with it directly, but be aware it exists. Do not delete or disable CLIUSR – the cluster uses it alongside certificates for bootstrapping. (All cluster node communications will now use either Kerberos or certificate auth; NTLM is not needed in WS2019+ clusters.) Now that you've backflipped and shenaniganed with all the certificates, you can actually get around to building the cluster. Creating the Failover Cluster (Using DNS as the Access Point) Here we will create the cluster and add nodes to it using PowerShell. The cluster will use a DNS name for its administrative access point (since there is no Active Directory for a traditional cluster computer object). The basic steps are: Validate the configuration (optional but recommended). Create the cluster (initially with one node to avoid cross-node authentication issues). Join additional node(s) to the cluster. Configure cluster networking, quorum, and storage (CSV). Validate the Configuration (Cluster Validation) It’s good practice to run the cluster validation tests to catch any misconfiguration or hardware issues before creating the cluster. Microsoft supports a cluster only if it passes validation or if any errors are acknowledged as non-critical. Run the following from one of the nodes (this will reach out to all nodes): Test-Cluster -Node Node1.mylocal.net, Node2.mylocal.net Replace with your actual node names (include all 2 or 4 nodes). The cmdlet will run a series of tests (network, storage, system settings). Ensure that all tests either pass or only have warnings that you understand. For example, warnings about “no storage is shared among all nodes” are expected if you haven’t yet configured iSCSI or if using SMB (you can skip storage tests with -Skip Storage if needed). If critical tests fail, resolve those issues (networking, disk visibility, etc.) before proceeding. Create the Cluster (with the First Node) On one node (say Node1), use the New-Cluster cmdlet to create the cluster with that node as the first member. By doing it with a single node initially, we avoid remote authentication at cluster creation time (no need for Node1 to authenticate to Node2 yet): New-Cluster -Name "Cluster1" -Node Node1 -StaticAddress "10.0.0.100" -AdministrativeAccessPoint DNS Here: -Name is the intended cluster name (this will be the name clients use to connect to the cluster, e.g. for management or as a CSV namespace prefix). We use “Cluster1” as an example. -Node Node1 specifies which server to include initially (Node1’s name). -StaticAddress sets the cluster’s IP address (choose one in the same subnet that is not in use; this IP will be brought online as the “Cluster Name” resource). In this example 10.0.0.100 is the cluster IP. -AdministrativeAccessPoint DNS indicates we’re creating a DNS-only cluster (no AD computer object). This is the default in workgroup clusters, but we specify it explicitly for clarity. The command will proceed to create the cluster service, register the cluster name in DNS (if DNS is configured and dynamic updates allowed), and bring the core cluster resources online. It will also create a cluster-specific certificate (self-signed) for internal use if needed, but since we have our CA-issued certs in place, the cluster may use those for node authentication. Note: If New-Cluster fails to register the cluster name in DNS (common in workgroup setups), you might need to create a manual DNS A record for “Cluster1” pointing to 10.0.0.100 in whatever DNS server the nodes use. Alternatively, add “Cluster1” to each node’s hosts file (as we did in prerequisites). This ensures that the cluster name is resolvable. The cluster will function without AD, but it still relies on DNS for name resolution of the cluster name and node names. At this point, the cluster exists with one node (Node1). You can verify by running cluster cmdlets on Node1, for example: Get-Cluster (should list “Cluster1”) and Get-ClusterNode (should list Node1 as up). In Failover Cluster Manager, you could also connect to “Cluster1” (or to Node1) and see the cluster. Add Additional Nodes to the Cluster Now we will add the remaining node(s) to the cluster: On each additional node, run the following (replace “Node2” with the name of that node and adjust cluster name accordingly): Add-ClusterNode -Cluster Cluster1 -Name Node2 Run this on Node2 itself (locally). This instructs Node2 to join the cluster named Cluster1. Because Node2 can authenticate the cluster (Node1) via the cluster’s certificate and vice versa, the join should succeed without prompting for credentials. Under the hood, the cluster service on Node2 will use the certificate (and CLIUSR account) to establish trust with Node1’s cluster service. Repeat the Add-ClusterNode command on each additional node (Node3, Node4, etc. one at a time). After each join, verify by running Get-ClusterNode on any cluster member – the new node should show up and status “Up”. If for some reason you prefer a single command from Node1 to add others, you could use: # Run on Node1: Add-ClusterNode -Name Node2, Node3 -Cluster Cluster1 This would attempt to add Node2 and Node3 from Node1. It may prompt for credentials or require TrustedHosts if no common auth is present. Using the local Add-ClusterNode on each node avoids those issues by performing the action locally. Either way, at the end all nodes should be members of Cluster1. Configure Quorum (Witness) Quorum configuration is critical, especially with an even number of nodes. The cluster will already default to Node Majority (no witness) or may try to assign a witness if it finds eligible storage. Use a witness to avoid a split-brain scenario. If you have a small shared disk (LUN) visible to both nodes, that can be a Disk Witness. Alternatively, use a Cloud Witness (Azure). To configure a disk witness, first make sure the disk is seen as Available Storage in the cluster, then run: Get-ClusterAvailableDisk | Add-ClusterDisk Set-ClusterQuorum -Cluster Cluster1 -NodeAndDiskMajority 0 /disk:<DiskResourceName> (Replace <DiskResourceName> with the name or number of the disk from Get-ClusterResource). Using Failover Cluster Manager, you can run the Configure Cluster Quorum wizard and select “Add a disk witness”. If no shared disk is available, the Cloud Witness is an easy option (requires an Azure Storage account and key). For cloud witness: Set-ClusterQuorum -Cluster Cluster1 -CloudWitness -AccountName "<StorageAccount>" -AccessKey "<Key>" Do not use a File Share witness – as noted earlier, file share witnesses are not supported in workgroup clusters because the cluster cannot authenticate to a remote share without AD. A 4-node cluster can sustain two node failures if properly configured. It’s recommended to also configure a witness for even-number clusters to avoid a tie (2–2) during a dual-node failure scenario. A disk or cloud witness is recommended (same process as above). With 4 nodes, you would typically use Node Majority + Witness. The cluster quorum wizard can automatically choose the best quorum config (typically it will pick Node Majority + Witness if you run the wizard and have a witness available). You can verify the quorum configuration with Get-ClusterQuorum. Make sure it lists the witness you configured (if any) and that the cluster core resources show the witness online. Add Cluster Shared Volumes (CSV) or Configure VM Storage Next, prepare storage for Hyper-V VMs. If using a shared disk (Block storage like iSCSI/SAN), after adding the disks to the cluster (they should appear in Storage > Disks in Failover Cluster Manager), you can enable Cluster Shared Volumes (CSV). CSV allows all nodes to concurrently access the NTFS/ReFS volume, simplifying VM placement and live migration. To add available cluster disks as CSV volumes: Get-ClusterDisk | Where-Object IsClustered -eq $true | Add-ClusterSharedVolume This will take each clustered disk and mount it as a CSV under C:\ClusterStorage\ on all nodes. Alternatively, right-click the disk in Failover Cluster Manager and choose Add to Cluster Shared Volumes. Once done, format the volume (if not already formatted) with NTFS or ReFS via any node (it will be accessible as C:\ClusterStorage\Volume1\ etc. on all nodes). Now this shared volume can store all VM files, and any node can run any VM using that storage. If using an SMB 3 share (NAS or file server), you won’t add this to cluster storage; instead, each Hyper-V host will connect to the SMB share directly. Ensure each node has access credentials for the share. In a workgroup, that typically means the NAS is also in a workgroup and you’ve created a local user on the NAS that each node uses (via stored credentials) – this is outside the cluster’s control. Each node should be able to New-SmbMapping or simply access the UNC path. Test access from each node (e.g. Dir \\NAS\HyperVShare). In Hyper-V settings, you might set the Default Virtual Hard Disk Path to the UNC or just specify the UNC when creating VMs. Note: Hyper-V supports storing VMs on SMB 3.0 shares with Kerberos or certificate-based authentication, but in a workgroup you’ll likely rely on a username/password for the share (which is a form of local account usage at the NAS). This doesn’t affect cluster node-to-node auth, but it’s a consideration for securing the NAS. Verify Cluster Status At this stage, run some quick checks to ensure the cluster is healthy: Get-Cluster – should show the cluster name, IP, and core resources online. Get-ClusterNode – all nodes should be Up. Get-ClusterResource – should list resources (Cluster Name, IP Address, any witness, any disks) and their state (Online). The Cluster Name resource will be of type “Distributed Network Name” since this is a DNS-only cluster. Use Failover Cluster Manager (you can launch it on one of the nodes or from RSAT on a client) to connect to “Cluster1”. Ensure you can see all nodes and storage. When prompted to connect, use <clustername> or <clusterIP> – with our certificate setup, it may be best to connect by cluster name (make sure DNS/hosts is resolving it to the cluster IP). If a certificate trust warning appears, it might be because the management station doesn’t trust the cluster node’s cert or you connected with a name not in the SAN. As a workaround, connect directly to a node in cluster manager (e.g. Node1), which then enumerates the cluster. Now you have a functioning cluster ready for Hyper-V workloads, with secure authentication between nodes. Next, we configure Hyper-V specific settings like Live Migration. Configuring Hyper-V for Live Migration in the Workgroup Cluster One major benefit introduced in Windows Server 2025 is support for Live Migration in workgroup clusters (previously, live migration required Kerberos and thus a domain). In WS2025, cluster nodes use certificates to mutually authenticate for live migration traffic. This allows VMs to move between hosts with no downtime even in the absence of AD. We will enable and tune live migration for our cluster. By default, the Hyper-V role might have live migration disabled (for non-clustered hosts). In a cluster, it may be auto-enabled when the Failover Clustering and Hyper-V roles are both present, but to ensure it it, run: Enable-VMMigration This enables the host to send/receive live migrations. In PowerShell, no output means success. (In Hyper-V Manager UI, this corresponds to ticking “Enable incoming and outgoing live migrations” in the Live Migrations settings.) In a workgroup, the only choice in UI would be CredSSP (since Kerberos requires domain). CredSSP means you must initiate the migration from a session where you are logged onto the source host so your credentials can be delegated. We cannot use Kerberos here, but the cluster’s internal PKU2U certificate mechanism will handle node-to-node auth for us when orchestrated via Failover Cluster Manager. No explicit setting is needed for cluster-internal certificate usage & Windows will use it automatically for the actual live migration operation. If you were to use PowerShell, the default MigrationAuthenticationType is CredSSP for workgroup. You can confirm (or set explicitly, though not strictly required): Set-VMHost -VirtualMachineMigrationAuthenticationType CredSSP (This can be done on each node; it just ensures the Hyper-V service knows to use CredSSP which aligns with our need to initiate migrations from an authenticated context.) If your cluster nodes were domain-joined, Windows Server 2025 enables Credential Guard which blocks CredSSP by default. In our case (workgroup), Credential Guard is not enabled by default, so CredSSP will function. Just be aware if you ever join these servers to a domain (or they were once joined to a domain before being demoted to a workgroup), you’d need to configure Kerberos constrained delegation or disable Credential Guard to use live migration. For security and performance, do not use the management network for VM migration if you have other NICs. We will designate the dedicated network (e.g. “LMNet” or a specific subnet) for migrations. You can configure this via PowerShell or Failover Cluster Manager. Using PowerShell, run the following on each node: # Example: allow LM only on 10.0.1.0/24 network (where 10.0.1.5 is this node's IP on that network) Set-VMMigrationNetwork 10.0.1.5 Set-VMHost -UseAnyNetworkForMigration $false The Set-VMMigrationNetwork cmdlet adds the network associated with the given IP to the allowed list for migrations. The second cmdlet ensures only those designated networks are used. Alternatively, if you have the network name or interface name, you might use Hyper-V Manager UI: under each host’s Hyper-V Settings > Live Migrations > Advanced Features, select Use these IP addresses for Live Migration and add the IP of the LM network interface. In a cluster, these settings are typically per-host. It’s a good idea to configure it identically on all nodes. Verify the network selection by running: Get-VMHost | Select -ExpandProperty MigrationNetworks. It should list the subnet or network you allowed, and UseAnyNetworkForMigration should be False. Windows can either send VM memory over TCP, compress it, or use SMB Direct (if RDMA is available) for live migration. By default in newer Windows versions, compression is used as it offers a balance of speed without special hardware. If you have a very fast dedicated network (10 Gbps+ or RDMA), you might choose SMB to leverage SMB Multichannel/RDMA for highest throughput. To set this: # Options: TCPIP, Compression, SMB Set-VMHost -VirtualMachineMigrationPerformanceOption Compression (Do this on each node; “Compression” is usually default on 2022/2025 Hyper-V.) If you select SMB, ensure your cluster network is configured to allow SMB traffic and consider enabling SMB encryption if security is a concern (SMB encryption will encrypt the live migration data stream). Note that if you enable SMB encryption or cluster-level encryption, it could disable RDMA on that traffic, so only enable it if needed, or rely on the network isolation as primary protection. Depending on your hardware, you may allow multiple VMs to migrate at once. The default is usually 2 simultaneous live migrations. You can increase this if you have capacity: Set-VMHost -MaximumVirtualMachineMigrations 4 -MaximumStorageMigrations 2 Adjust numbers as appropriate (and consider that cluster-level property (Get-Cluster).MaximumParallelMigrations might override host setting in a cluster). This setting can also be found in Hyper-V Settings UI under Live Migrations. With these configured, live migration is enabled. Test a live migration: Create a test VM (or if you have VMs, pick one) and attempt to move it from one node to another using Failover Cluster Manager or PowerShell: In Failover Cluster Manager, under Roles, right-click a virtual machine, choose Live Migrate > Select Node… and pick another node. The VM should migrate with zero downtime. If it fails, check for error messages regarding authentication. Ensure you initiated the move from a node where you’re an admin (or via cluster manager connected to the cluster with appropriate credentials). The cluster will handle the mutual auth using the certificates (this is transparent – behind the scenes, the nodes use the self-created PKU2U cert or our installed certs to establish a secure connection for VM memory transfer). Alternatively, use PowerShell: Move-ClusterVirtualMachineRole -Name "<VM resource name>" -Node <TargetNode> This cmdlet triggers a cluster-coordinated live migration (the cluster’s Move operation will use the appropriate auth). If the migration succeeds, congratulations – you have a fully functional Hyper-V cluster without AD! Security Best Practices Recap and Additional Hardening Additional best practices for securing a workgroup Hyper-V cluster include: Certificate Security: The private keys of your node certificates are powerful – protect them. They are stored in the machine store (and likely marked non-exportable). Only admins can access them; ensure no unauthorized users are in the local Administrators group. Plan a process for certificate renewal before expiration. If using an enterprise CA, you might issue certificates with a template that allows auto-renewal via scripts or at least track their expiry to re-issue and install new certs on each node in time. The Failover Cluster service auto-generates its own certificates (for CLIUSR/PKU2U) and auto-renews them, but since we provided our own, we must manage those. Stagger renewals to avoid all nodes swapping at once (the cluster should still trust old vs new if the CA is the same). It may be wise to overlap: install new certs on all nodes and only then remove the old, so that at no point a node is presenting a cert the others don't accept (if you change CA or template). Trusted Root and Revocation: All nodes trust the CA – maintain the security of that CA. Do not include unnecessary trust (e.g., avoid having nodes trust public CAs that they don’t need). If possible, use an internal CA that is only used for these infrastructure certs. Keep CRLs (Certificate Revocation Lists) accessible if your cluster nodes need to check revocation for each other’s certs (though cluster auth might not strictly require online revocation checking if the certificates are directly trusted). It’s another reason to have a reasonably long-lived internal CA or offline root. Disable NTLM: Since clustering no longer needs NTLM as of Windows 2019+, you can consider disabling NTLM fallback on these servers entirely for added security (via Group Policy “Network Security: Restrict NTLM: Deny on this server” etc.). However, be cautious: some processes (including cluster formation in older versions, or other services) might break. In our configuration, cluster communications should use Kerberos or cert. If these servers have no need for NTLM (no legacy apps), disabling it eliminates a whole class of attacks. Monitor event logs (Security log events for NTLM usage) if you attempt this. The conversation in the Microsoft tech community indicates by WS2022, cluster should function with NTLM disabled, though a user observed issues when CLIUSR password rotated if NTLM was blocked. WS2025 should further reduce any NTLM dependency. PKU2U policy: The cluster uses the PKU2U security provider for peer authentication with certificates. There is a local security policy “Network security: Allow PKU2U authentication requests to this computer to use online identities” – this must be enabled (which it is by default) for clustering to function properly. Some security guides recommend disabling PKU2U; do not disable it on cluster nodes (or if your organization’s baseline GPO disables it, create an exception for these servers). Disabling PKU2U will break the certificate-based node authentication and cause cluster communication failures. Firewall: We opened WinRM over 5986. Ensure Windows Firewall has the Windows Remote Management (HTTPS-In) rule enabled. The Failover Clustering feature should have added rules for cluster heartbeats (UDP 3343, etc.) and SMB (445) if needed. Double-check that on each node the Failover Cluster group of firewall rules is enabled for the relevant profiles (if your network is Public, you might need to enable the rules for Public profile manually, or set network as Private). Also, for live migration, if using SMB transport, enable SMB-in rules. If you enabled SMB encryption, it uses the same port 445 but encrypts payloads. Secure Live Migration Network: Ideally, the network carrying live migration is isolated (not routed outside of the cluster environment). If you want belt-and-suspenders security, you could implement IPsec encryption on live migration traffic. For example, require IPsec (with certificates) between the cluster nodes on the LM subnet. However, this can be complex and might conflict with SMB Direct/RDMA. Another simpler approach: since we can rely on our certificate mutual auth to prevent unauthorized node communication, focus on isolating that traffic so even if someone tapped it, you can optionally turn on SMB encryption for LM (when using SMB transport) which will encrypt the VM memory stream. At minimum, treat the LM network as sensitive, as it carries VM memory contents in clear text if not otherwise encrypted. Secure WinRM/management access: We configured WinRM for HTTPS. Make sure to limit who can log in via WinRM. By default, members of the Administrators group have access. Do not add unnecessary users to Administrators. You can also use Local Group Policy to restrict WinRM service to only allow certain users or certificate mappings. Since this is a workgroup, there’s no central AD group; you might create a local group for “Remote Management Users” and configure WSMan to allow members of that group (and only put specific admin accounts in it). Also consider enabling PowerShell Just Enough Administration (JEA) if you want to delegate specific tasks without full admin rights, though that’s advanced. Hyper-V host security: Apply standard Hyper-V best practices: enable Secure Boot for Gen2 VMs, keep the host OS minimal (consider using Windows Server Core for fewer attack surface, if feasible), and ensure only trusted administrators can create or manage VMs. Since this cluster is not in a domain, you won’t have AD group-based access control; consider using Authentication Policies like LAPS for unique local admin passwords per node. Monitor cluster events: Monitor the System event log for any cluster-related errors (clustering will log events if authentication fails or if there are connectivity issues). Also monitor the FailoverClustering event log channel. Any errors about “unable to authenticate” or “No logon servers” etc., would indicate certificate or connectivity problems. Test failover and failback: After configuration, test that VMs can failover properly. Shut down one node and ensure VMs move to other node automatically. When the node comes back, you can live migrate them back. This will give confidence that the cluster’s certificate-based auth holds up under real failover conditions. Consider Management Tools: Tools like Windows Admin Center (WAC) can manage Hyper-V clusters. WAC can be configured to use the certificate for connecting to the nodes (it will prompt to trust the certificate if self-signed). Using WAC or Failover Cluster Manager with our setup might require launching the console from a machine that trusts the cluster’s cert and using the cluster DNS name. Always ensure management traffic is also encrypted (WAC uses HTTPS and our WinRM is HTTPS so it is).
Windows Activation Error 0x80072F8F
Hi, I'm getting the below error code 0x80072F8F when trying to activate the windows (Windows server 2008 R2). Though i tried the following methods to resolve the issue unfortunately issue remains the same Method 1: I checked the date, time, year in BIOS and on windows as well and they were accurate. I also set the date or year back and restarted the system (set date one year back, reboot, set actual date, reboot, activate) but no luck Method 2: Changed the media boot install registry key from 1 to 0 Kindly let me know if there is any workaround to activate windows other than the above mentioned methods. Thanks in advance
Server 2025 not accepting Ricoh scans
The scanner has stopped scanning to their server since I upgraded the server OS from Windows Server 2022 to 2025. • Installed the Ricoh drivers for both the scanner and printer (from Ricoh’s web site) • Created a new simple share/filepath for the scanner to send to (\\SERVER2022\Scans) • Used IP address (10.1.10.2) instead of server name in file (UNC) path • Entered admin credentials with or without server name (it is a workgroup server, not a DC) • Created another user and tried all above with that new admin • With either server share and/or user, tried different permissions on the shared folder • Tried disabling/enabling inherited permissions on the shared folder • Disabled the Advanced Firewall entirely for testing – no change either way • Double checked incoming ports/programs on the firewall – all required were open • Activated SMB1 on server, tried with or without SMB2/SMB3 disabled • I was able to create a share on two other computers; one running Windows 10 and one running Windows 11. They both worked.
ASP Classic stop working after Windows Server 2012 for x64-based System KB5073698
I hope this will be useful to others. We have a legacy application implemented using classic ancient ASP after the most recent windows server rollup update the ASP pages stop working, without any error message, the worker thread just crashed. It turned out that the network stack was hardened and the old ASP engine did not expect a failure on network operations. I did a short write up here with the solution https://www.linkedin.com/pulse/classic-asp-bug-took-four-days-solve-ridiculous-root-cause-pedruzzi-adw9e
Announcing Native NVMe in Windows Server 2025: Ushering in a New Era of Storage Performance
We’re thrilled to announce the arrival of Native NVMe support in Windows Server 2025—a leap forward in storage innovation that will redefine what’s possible for your most demanding workloads. Modern NVMe (Non-Volatile Memory Express) SSDs now operate more efficiently with Windows Server. This improvement comes from a redesigned Windows storage stack that no longer treats all storage devices as SCSI (Small Computer System Interface) devices—a method traditionally used for older, slower drives. By eliminating the need to convert NVMe commands into SCSI commands, Windows Server reduces processing overhead and latency. Additionally, the whole I/O processing workflow is redesigned for extreme performance. This release is the result of close collaboration between our engineering teams and hardware partners, and it serves as a cornerstone in modernizing our storage stack. Native NVMe is now generally available (GA) with an opt-in model (disabled by default as of October’s latest cumulative update for WS2025). Switch onto Native NVMe as soon as possible or you are leaving performance gains on the table! Stay tuned for more updates from our team as we transition to a dramatically faster, more efficient storage future. Why Native NVMe and why now? Modern NVMe devices—like PCIe Gen5 enterprise SSDs capable of 3.3 million IOPS, or HBAs delivering over 10 million IOPS on a single disk—are pushing the boundaries of what storage can do. SCSI-based I/O processing can’t keep up because it uses a single-queue model, originally designed for rotational disks, where protocols like SATA support just one queue with up to 32 commands. In contrast, NVMe was designed from the ground up for flash storage and supports up to 64,000 queues, with each queue capable of handling up to 64,000 commands simultaneously. With Native NVMe in Windows Server 2025, the storage stack is purpose-built for modern hardware—eliminating translation layers and legacy constraints. Here’s what that means for you: Massive IOPS Gains: Direct, multi-queue access to NVMe devices means you can finally reach the true limits of your hardware. Lower Latency: Traditional SCSI-based stacks rely on shared locks and synchronization mechanisms in the kernel I/O path to manage resources. Native NVMe enables streamlined, lock-free I/O paths that slash round-trip times for every operation. CPU Efficiency: A leaner, optimized stack frees up compute for your workloads instead of storage overhead. Future-Ready Features: Native support for advanced NVMe capabilities like multi-queue and direct submission ensures you’re ready for next-gen storage innovation. Performance Data Using DiskSpd.exe, basic performance testing shows that with Native NVMe enabled, WS2025 systems can deliver up to ~80% more IOPS and a ~45% savings in CPU cycles per I/O on 4K random read workloads on NTFS volumes when compared to WS2022. This test ran on a host with Intel Dual Socket CPU (208 logical processors, 128GB RAM) and a Solidigm SB5PH27X038T 3.5TB NVMe device. The test can be recreated by running "diskspd.exe -b4k -r -Su -t8 -L -o32 -W10 -d30 testfile1.dat > output.dat" and modifying the parameters as desired. Results may vary. Top Use Cases: Where You’ll See the Difference Try Native NVMe on servers running your enterprise applications. These gains are not just for synthetic benchmarks—they translate directly to faster database transactions, quicker VM operations, and more responsive file and analytics workloads. SQL Server and OLTP: Shorter transaction times, higher IOPS, and lower tail latency under mixed read/write workloads. Hyper‑V and virtualization: Faster VM boot, checkpoint operations, and live migration with reduced storage contention. High‑performance file servers: Faster large‑file reads/writes and quicker metadata operations (copy, backup, restore). AI/ML and analytics: Low‑latency access to large datasets and faster ETL, shuffle, and cache/scratch I/O. How to Get Started Check your hardware: Ensure you have NVMe-capable devices that are currently using the Windows NVMe driver (StorNVMe.sys). Note that some NVMe device vendors provide their own drivers, so unless using the in-box Windows NVMe driver, you will not notice any differences. Enable Native NVMe: After applying the 2510-B Latest Cumulative Update (or most recent), add the registry key with the following PowerShell command: reg add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Policies\Microsoft\FeatureManagement\Overrides /v 1176759950 /t REG_DWORD /d 1 /f Alternatively, use this Group Policy MSI to add the policy that controls the feature then run the local Group Policy Editor to enable the policy (found under Local Computer Policy > Computer Configuration > Administrative Templates > KB5066835 251014_21251 Feature Preview > Windows 11, version 24H2, 25H2). Once Native NVMe is enabled, open Device Manager and ensure that all attached NVMe devices are displayed under the “Storage disks” section. Monitor and Validate: Use Performance Monitor and Windows Admin Center to see the gains for yourself. Or try DiskSpd.exe yourself to measure microbenchmarks in your own environment! A quick way to measure IOPS in Performance Monitor is to set up a histogram chart and add a counter for Physical Disk>Disk Transfers/sec (where the selected instance is a drive that corresponds to one of your attached NVMe devices) then run a synthetic workload with DiskSpd. Compare the numbers before and after enabling Native NVMe to see the realized difference in your real environment! Join the Storage Revolution This is more than just a feature—it’s a new foundation for Windows Server storage, built for the future. We can’t wait for you to experience the difference. Share your feedback, ask questions, and join the conversation. Let’s build the future of high-performance Windows Server storage together. Send us your feedback or questions at nativenvme@microsoft.com! — Yash Shekar (and the Windows Server team)
Windows Server 2025 24H4 is not useable anymore after Nov. Update KB5068861
Hello, currently, on several Windows Server 2025 Datacenter systems, version 24H2, I am experiencing severe issues accessing network resources after the automatic installation of update KB5068861. This affects network access from Windows Server 2025 24H2 to Windows Server 2025 24H2. Access from these servers to older Windows Server 2016 systems works without any problems. When entering a UNC path—whether by name or by IP—I am always prompted for my credentials, even as a domain administrator. No matter which credentials I enter, I always receive the message that the username or password is incorrect. Under “Change advanced sharing settings,” the two switches “Network discovery” and “File and printer sharing” are set to OFF in the domain network after the update. Re-enabling these two options, which are normally enabled by default, does not improve the situation. Since this patch, I also have an issue on a Windows Server 2025 RDS host where a logged-in user cannot type in the “Search” field. Additionally, the performance on the RDS host feels extremely sluggish. Unfortunately, uninstalling the patch is not possible. The patch KB5067036 is not installed. I have already performed a restore to the day before KB5068861 was installed, but without the desired improvement in performance. Even after the restore, I still cannot access the network via UNC through File Explorer as a user. In the search window, I can access via UNC path. As an administrator, access via UNC path works both in File Explorer and in the “Search” field. Everything worked fine before 11/11/2025. Has anyone had similar experiences or already found a solution? Is a patch for the patch planned? Currently, troubleshooting feels like groping in the dark! In this state, the 24H2 server is no longer usable. What was Microsoft even thinking, releasing such faulty patches—and for weeks now? Is there still any quality control at Microsoft for such critical updates and patches? Thanks for every support, idea, and comment.
What's the deal with Kerb3961?
Howdy, everyone! I wanted to write this blog post to discuss the new Kerb3961 library introduced in Windows Server 2025 / Windows 11 24H2. It is (hopefully) making encryption type (etype) usage within Kerberos much easier to anticipate and understand. Let's start with... What is Kerb3961? Kerb3961, named after RFC3961, is a refactor of the Kerberos cryptography engine in its own library. This library is now the authoritative source of: Etype selection Etype usage Etype management For the average IT administrator, the part that is going to be most interesting is #1. The Kerb3961 policy engine is what will authoritatively determine what etypes are available given different Kerberos key usage scenarios. Whereas in previous Windows releases, there were instances of hard coded etype usage due to technical limitations at the time of implementation. Kerb3961 still leverages existing Kerberos etype configuration group policy: Network security Configure encryption types allowed for Kerberos - Windows 10 | Microsoft Learn. However, it no longer honors the legacy registry key path of: HKEY_LOCAL_MACHINE\CurrentControlSet\Control\Lsa\Kerberos\Parameters REG_DWORD SupportedEncryptionTypes As a reminder, the group policy mentioned above is used to configure the supported encryption types for a machine account. The machine then propagates this information into Active Directory (AD) where it is stored in the msds-SupportedEncryptionType attribute for the account. It has no effect on non-etype related Kerberos settings such as those outlined in Registry entries about Kerberos protocol and Key Distribution Center (KDC) with the exception of the DefaultDomainSupportedEncTypes registry key. The biggest change is the reduction of hard-coded etype usage. We have heard the frustrations of customers who are trying to eliminate RC4 usage, and the seemingly unexplainable instances of RC4 usage with their environments. This new library removes these hard-coded dependencies and aggregates all those decisions into one place. With the goal of: More secure Kerberos operations by default More predictable Kerberos etype usage More stable etype additions More stable etype removals For example, if we had not done this refactor, the DES deprecation and on-going work towards RC4 deprecation would not be possible. Why did this need to happen? Kerberos was added to Windows in the early 2000's as a part of beginning the move away from NTLM and into modern cipher usage. Over these decades, there have been incredible strides in security hardening that the original developers could not have foreseen. As a result, some of the design decisions made during that initial implementation impacted our ability to reliably change the way Kerberos operates. This can be seen in things like: Kerberos changes for CVE-2022-37966 Kerberos changes for CVE-2022-37967 Additionally, with the long tail of code in this area and the etype that has been historically used, it had become a near impossibility to add or remove a cipher due to how the etypes were directly associated in Kerberos. What does this mean going forward? The Kerb3961 library has key implications going forward. The biggest one is the removal of hard-coded cipher usage and a stronger adherence to the administrators’ configured encryption types. The environment will operate as configured. Meaning IT administrators can have a high degree of confidence that their configurations will be honored. This increases the amount of knowledge required by administrators. Misconfigurations, previously hidden by loose adherence to the configured etypes, will now be exposed. For more information about Kerberos etype selection, refer to the Kerberos EType Calculator. What needs to be done? To configure an environment requires understanding what etypes are used within an environment. To help aid in this endeavor, we have improved Key Distribution Center (KDC) auditing. 4768(S, F) A Kerberos authentication ticket (TGT) was requested. - Windows 10 | Microsoft Learn 4769(S, F) A Kerberos service ticket was requested. - Windows 10 | Microsoft Learn We have also published two PowerShell helper scripts that leverage these new events. The goal of these scripts is to allow for easier identification of both etype usage and account key availability. These scripts are published on the Microsoft Kerberos-Crypto GitHub repository, where, going forward, we will be using scripts and information published there to better interface with the community. We acknowledge that substantial changes can introduce regressions and friction points for those with mature environments. It is our goal to allow for a smooth adoption of these new features and prevent any unnecessary pain for our already overworked and under-appreciated system administrators. Please be sure to leverage Feedback Hub to share your experiences with us. If you would like to see any of these features early, we highly recommend leveraging the Windows Insider Program and opting into Continuous Innovation and sharing feedback directly with the development team. We understand that this can be challenging, and Microsoft is committed to ensuring that the knowledge needed to make an informed decision about what is right for your environment.Introducing the VM Conversion tool in Windows Admin Center – Public Preview
As organizations update their infrastructure, a growing number are seeking adaptable, Microsoft-supported solutions that address current requirements while laying the path for future cloud and AI adoption. Azure provides an agile, scalable, cost-effective platform for infrastructure and innovation. Whether by modernizing to cloud technologies like Windows or Linux VMs, containers, Azure VMware Solution or PaaS services, Azure offers a world-class cloud experience. However, we recognize that some organizations must retain workloads on-premises due to data compliance, governance, or other regulatory requirements. For customers wanting to adopt Windows Server and Hyper-V for this use case, we are excited to provide a new option within Windows Admin Center, the VM Conversion tool, in public preview now. This agentless, cost-free tool streamlines the conversion of virtual machines from VMware to Windows Server with Hyper-V, providing customers flexibility with their on-premises virtualization environments while enabling a seamless transition path to Azure when desired. With minimal infrastructure requirements, the tool is particularly beneficial for small and medium-sized organizations. Additionally, with minimal setup time you can download the new VM Conversion tool extension in Windows Admin Center and begin converting virtual machines in under five minutes. Figure 1- VM Conversion tool in Windows Admin Center 🔑Key Features : Agentless, appliance-free discovery After establishing a connection to the virtualization environment, the tool conducts discovery of all virtual machines without requiring agents or appliances and does so in a non-intrusive manner. Minimal downtime The VM Conversion tool enables initial data replication while the source virtual machine remains operational, thereby preventing any interruptions to ongoing applications. After completing this initial replication, on user consent, the source VM is powered down so a subsequent replication pass can capture any data changes made during the first phase. This two-step process ensures that the cutover time from the source to the target VM is minimized. Group servers You can select and migrate up to 10 virtual machines at a time. This reduces manual effort and accelerates the transition to Windows Server. Boot configuration The tool automatically maps BIOS-based virtual machines to Generation 1 and UEFI-based machines to Generation 2, preserving boot configurations and ensuring compatibility. OS agnostic The tool supports conversion of both Linux and Windows guest OS VMs to Windows Server host. Multi-disk VM support Virtual machines that use several virtual hard disks—common in production environments—are fully supported. The operating system, data, and application disks all migrated together, so manual setup is not needed. ⚙️How It Works To ensure a smooth and reliable transition, the tool performs a comprehensive set of built-in prechecks. These checks validate critical VM attributes such as disk types, boot configuration (BIOS or UEFI), destination disk, memory requirements, and several more. By identifying potential issues early, administrators can proactively address them—minimizing the risk of migration failures and reducing downtime during the final cutover. The VM Conversion tool uses change block tracking (CBT) to efficiently replicate data from one virtual disk format to another. During the initial seeding phase, a full copy of the virtual machine is created while it remains online. This minimizes downtime and ensures data integrity. Before the final cutover, a delta replication captures all changes made since the initial copy, ensuring the destination VM is fully up-to-date post conversion to Hyper-V hosts. 🚀Ready to Take the Next Step? The VM Conversion tool is available now in the public feed of Windows Admin Center. You can install it directly from the Extensions settings in Windows Admin Center. To get started, ensure you're running the Windows Admin Center v2 GA release. 📘 For detailed setup instructions and prerequisites, refer to the Public Preview Documentation. 📍 Summary The VM Conversion tool offers a simple, supported path for organizations to streamline VM conversion to Hyper-V virtualization environments. With no added cost and minimal setup, it empowers customers to streamline VM migration and prepare for the cloud at their own pace. Support for Azure Arc-enabled servers is also planned for future releases, further enhancing hybrid management capabilities. We’re continuously evolving the VM Conversion tool based on user feedback. Please continue to share your feedback here and help us prioritize our efforts for future releases. Happy converting!Cache drive reconfiguration in Server 2025 Storage Spaces Direct cluster
We have a three node S2D cluster running Server 2025, with the storage in a 3 way mirror, running Hyper-V VMs. Each node has 4 x NVMe drives that are currently being used as cache drives, but which are connected to a RAID controller (in HBA mode), so in the S2D configuration they appear as SSD drives rather than NVMe drives. We've purchased the required cables and drive bays to be able to reconfigure the NVMe drives so that they're attached directly to the PCIe bus, so they'll show up as NVMe drives and hopefully give us a performance boost, so I'm just trying to plan the reconfiguration. I was hoping it would be a relatively simple process of shutting everything down, reconfiguring the storage and bringing everything back online, but ChatGPT suggests things won't be that easy and that a complete reconfiguration of the storage would be required. So in a nutshell, can the cache drives be reconfigured without a complete rebuild of the S2D storage ? Cheers, RobIssues with Group Policy Update (gpupdate)
I am getting an error when I attempt to perform a gpupdate /force on workstations. I have checked the health of the DC's and find no issues. I am going to include a screenshot of the error - hoping someone can guide me as on how to resolve. The system will say to reboot but the policy never seems to run just keeps prompting for reboot.
