Tag:"hyper-v" | Microsoft Community Hub

Untagged VLAN - Server 2025 Hyper-V
Hi, I have a strage issue and not finding a solution. Using Server 2025 with two node Hyper-V cluster. Most of the machines using VLANs which works fine. Some machines using no VLAN config. Which usually means the "Access VLAN 1" regarding our switch configuration. With Server 2019 this worked fine. With Server 2025 same NIC port, same server/NIC hardware "Untagged" VMs don't get any network connection. If I add a second NIC to the VM "Untagged" the NIC get immidiatly an IP address and has a proper connection. If I remove the first NIC, the second NIC stop working. It looks like something has changed with Server 2025 (maybe already with Server 2022). Do you have any idea what kinde of problem I have found? Thanks Jack
JackThunder
Apr 16, 2025 Place Windows Server for IT Pro
100Views
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2Comments
PowerShell counterpart for Failover Cluster Manager "Live Migration Settings"
In Failover Cluster Manager, there's "Live Migration Settings" where I can define what cluster networks I want to carry live migration traffic. Even after some research, I cannot find a PowerShell cmdlet that lets me do the same...
ahinterl
Apr 15, 2025 Place Windows Server for IT Pro
22Views
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Hyper-V SMB UNC LocalIP/name avoiding loopback
Hello, I have the following scenario: Two standalone servers joined to a domain (I can't set up a failover cluster at the moment) What I want to achieve is: Access the storage resources via UNC SMB paths in order to perform a storage migration from both nodes \\svhpv1\VMs \\svhpv2\VMs But when I try to have svhpv1 access \\svhpv1\VMs, I get an "Access Denied" error. I believe this error occurs because the access is being attempted through the loopback adapter. I’m experiencing the same issue with svhpv2 when trying to access \\svhpv2\VMs. How can I avoid the loopback so I can properly configure my scenario? Any help is appreciated.
jmarsj
Apr 13, 2025 Place Windows Server for IT Pro
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NUMA Problems after In-Place Upgrade 2022 to 2025
We have updated several Hyper-V hosts with AMD Milan processors from Windows 2022 to Windows 2025 using the in-place update method. We are encountering an issue where, after starting about half of the virtual machines, the remaining ones fail to start due to a resource shortage error. The host's RAM is about 70% free. We can only get them to start by enabling the "Allow Spanning" configuration, but this reduces performance, and with so many free resources, this shouldn't be happening. Has anyone else experienced something similar? What has changed in 2025 to cause this issue? The error is: Virtual machine 'R*****2' cannot be started on this server. The virtual machine NUMA topology requirements cannot be satisfied by the server NUMA topology. Try to use the server NUMA topology, or enable NUMA spanning. (Virtual machine ID CA*****3-ED0E-4***4-A****C-E01F*********C4). Event ID: 10002 <EventRecordID>41</EventRecordID> <Correlation /> <Execution ProcessID="5524" ThreadID="8744" /> <Channel>Microsoft-Windows-Hyper-V-Compute-Admin</Channel> <Computer>HOST-JLL</Computer>
festuc
Apr 10, 2025 Place Windows Server for IT Pro
120Views
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3Comments
Bypass LBFO Teaming deprecation on Hyper-V and Windows Server 2022
Starting with Windows Server 1903 and 1909, Hyper-V virtual switches on an LBFO-type network adapter cluster are deprecated (see documentation). The technology remains supported, but it will not evolve. It is recommended to create an aggregate of type SET. In practice The SET is a very interesting technology that has some constraints. The interfaces used must have identical characteristics: Manufacturer Model Link speed Configuration Even if these constraints do not seem huge, we are very far from the flexibility of LBFO Teaming. As a reminder, this one has absolutely no constraints. In practice the SET is recommended with network interfaces of 10Gb or more. Therefore, we are very far from the target of the LBFO (use of all integrated boards with motherboard pro, Home Lab, refurbish). If SET cannot be used As of Windows Server 2022, it is not possible to use the Hyper-V Management Console to create a virtual switch with LBFO, as it will prompt an error saying that LBFO have been depreciated. However, it is possible to use PowerShell to create this virtual switch. First, create the Teaming of your network cards using the Server Manager, in my case the teaming will be with LACP mode and Dynamic load balancing mode. Then execute the below PowerShell Command to create the virtual switch based on the teaming created in the previous step: New-VMSwitch -Name "LAN" -NetAdapterName "LINK-AGGREGATION" -AllowNetLbfoTeams $true -AllowManagementOS $true In detail: The virtual switch will be named "LAN" The network adapter cluster teaming is named "LINK-AGGREGATION" The aggregate remains usable to access the Hyper-V host. You will see your network teaming up and running on Hyper-V host. Thats it!
eliekarkafy
Apr 04, 2025 Place Windows Server for IT Pro
140KViews
5likes
10Comments
PowerShell, Hyper-V: Examine network object relationships.
Is it possible in PowerShell do do things like: Get all VMNetworkAdapters connected to a given VMSwitch Get all VMNetworkAdapters provided by a hypervisor (conected to either a VM or the management OS) When I have the name of a VMNetworkAdapter only, determine whether it's connected to the management OS, or a VM, and if connected to a VM, what VM that is without examining each single endpoint (VM, management OS) and creating a database of objects and their relationships that allows me to get the desired information? Certainly not a couple of PowerShell code lines only, and depending on the size and type (remote, local) of the virtualization environment, I can imagine that time is a factor too.
ahinterl
Mar 26, 2025 Place Windows Server for IT Pro
83Views
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2Comments
Increase the size of user profile disk in my remote desktop server
Hi all experts. I have a server for remote desktop services purposes, Windows 2016 standard, and domain joined. It is configured using User Profile Disk, and the maximum limit is set to 5GB. I want to increase the maximum limit but I can't do it under the collection's properties because that field is grayed out. My questions: How to increase the maximum limit? Please guide me and let me know how. Can I increase the maximum limit for 1 single user only? If yes, please let me know how. I found some info from the web that this can be done by the Diskpart command, is it true? If I follow the Diskpart method, do all user profiles encounter data lost? I need your guidance and input, I appreciate it. Here are some images:
Solved
szuguan
Mar 13, 2025 Place Windows Server for IT Pro
578Views
0likes
6Comments
Hyper-V: How do VMs communicate with external?
Simple scenario: VM --> vNIC --> vSwitch (external) --> physNIC --> physSwitch The vNIC assigned to the VM has MAC address aa:aa:aa:aa:aa:aa, the physical NIC (physNIC; the vSwitch of type external is connected to it) has bb:bb:bb:bb:bb:bb. What mechanism ensures that when the VM sends a network packet to the external network (the physical network connected to the physical switch physSwitch), the MAC address of its vNIC (aa:aa:aa:aa:aa:aa) is used, and not the MAC address of the physNIC (bb:bb:bb:bb:bb:bb)? In other words: what makes physSwitch "see" aa:aa:aa:aa:aa:aa when the VM communicates to an external endpoint?
ahinterl
Mar 10, 2025 Place Windows Server for IT Pro
30Views
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Launching EXEs on File Server Slow on Hyper-V Host
We have a Server 2019 Hyper-V host that hosts a Server 2008 file server (yeah, I know, too old) and other virtual machines we use as work stations that access various EXE files on the file server. Recently, (not sure when it's started) launching EXE files stored on the 2008 server from one of the workstations (all on the same host) is getting delayed, sometimes as long as 20-30 seconds. An odd thing is that when you first log on to the work station and run the EXE it starts in what I think is a reasonable time, until now a second launch would be a little faster, I'm assuming due to caching. But not, launching it a second time gets the delay. Other file types seem to be OK. Opening large PDFs, for instance, does not have the problem. Working on a virtual machine hosted on our OTHER, older 2012 R2 Hyper-V host (yeah, again, I know) and going across the network, host to host, to access those same EXE files never has the delay problem. Because of virtual machines the 2012 host not having the problem, I'm thinking there's something on the 2019 host that's been updated. Update history shows KB5052000 installed in February and KB5050182 in January. I see that the January update mentions "Remote Code Execution" but the info seems to be specific to Visual Studio so I'm not sure that would apply. Has anyone seen this behavior or can maybe give me a clue as to where to start even looking? Thanks, Ken
KenK1110
Mar 07, 2025 Place Windows Server for IT Pro
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What MAC address
Create a new virtual switch and connect the management OS to it: New-VMSwitch -Name 'Ext' -AllowManagementOS $true -NetAdapterName 'Prod' A new VMNetworkAdapter was created, get name and MAC address: Get-VMNetworkAdapter -ManagementOS | Format-Table -Property 'Name', 'MacAddress' The MAC address is for example: 00155D05ED13 (the first three octets indicate "Microsoft"). Get MAC address pool of the Hyper-V host: Get-VMHost | Select 'MacAddressMinimum', 'MacAddressMaximum' | Format-Table My understanding is that this pool is used when creating VMNetworkAdapters for VMs. What I see in my case is that the MAC address of the new VMNetworkAdapter is different from the possible pool values. Question: From what pool are MAC addresses pulled for VMNetworkAdapters that are located in the management OS realm?
ahinterl
Feb 28, 2025 Place Windows Server for IT Pro
66Views
0likes
3Comments