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Hyper-V is a native hypervisor; it can create virtual machines on x86-64 systems and supersedes Windows Virtual PC as the hardware virtualization component of the client editions of Windows NT. A server computer running Hyper-V can be configured to expose individual virtual machines to one or more networks. Hyper-V Server supports remote access via Remote Desktop Connection. Administration and configuration of the host OS and the guest virtual machines is generally done over the network.

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Server 2012 r2 hyper-v hosted domain controller, windows 7 domain PCs.
After an ungrateful shutdown (power outage over an hour) Rebooted servers and workstations to find broken trust relationships on many workstations and servers.  Resetting machine password works for some but not all machines.
PCs that are moved to a workgroup and then back to a domain work until they are rebooted, then trust is broken again.
What is going on here??
Visualize your virtual and backup environments
Visualize your virtual and backup environments

Create well-organized and polished visualizations of your virtual and backup environments when planning VMware vSphere, Microsoft Hyper-V or Veeam deployments. It helps you to gain better visibility and valuable business insights.

Hi, I am trying to determine if I have Hyper-V manager server role configured correctly for my virtual environment.  In particular, virtual switch manager.  Why is it using an actual IP address from my network?  And is this necessary?  If not, how can I go about allowing it to reach my DHCP server on the network for the VM's that reside on the Hyper-V host server, yet not use an IP address from my very limited available IP's on my server network?

Hyper-V Host Servers:  Microsoft Windows Server 2012 R2 - Standard & DataCenter editions

Let me know if you require further details/information to answer these questions.

Thanks in advance.
I have a Dell r320 server running Windows 2012 r2 server hosting 2 Hyper-V Virtual Machines.  About once a week, the server and both VMs come to a slow crawl.  My event viewer shows no major events at all.  Suggestions?
I'm facing an issue with my Hyper-v host 1 . last couple of days when the backup job run to backup hyper-v host including virtual machines . I get below error and virtual machines lose network connectivity and loses the failover cluster communication .

"Failed to allocate VMQ for NIC B038F6F3-B1DB-48CF-9566-A98A0E7340F0--D5DAA699-7131-42C1-B895-3658D6F16959 (Friendly Name: Network Adapter) on switch 91306166-6B98-498C-B029-D552838FCD61 (Friendly Name: External). Reason - Maximum number of VMQs supported on the Protocol NIC is exceeded. Status = Insufficient system resources exist to complete the API. "

usually the virtual machines can be reached on network in 15 minutes . but its been 8 hours a mailbox server virtual machine is not accessible through network and i have tried accessing through hyper-v manager but its unresponsive .even i tried shutting down from hyper-v manager but throws me error. Is there any way to access the unresponsive mailbox virtual machine other than turning it off from hyper-v manager at the moment make the mailbox server up.
I'm desperately waiting for a help .
Thanks in advance.
PS:- hyper-v host in windows server 2012 standard
Hyper-v virtual machine is exchange 2013 enterprise mailbox server
This is a new one for me.  I have lots of hours on Hyper-V 2008 R2 and 2012 R2.  I have lots of hours on fail over clusters with HPE Proliant DL380 GenX servers with MSA storage.  I am aware of the Broadcom driver bug that requires disabling VMQ.  I built a new Windows 2016 Hyper-V fail over cluster on HPE Proliant DL380 Gen9 servers and MSA storage.  Everything working perfectly, except networking.

The VMs on the cluster CAN obtain DHCP addresses form a server elsewhere on the network (or I can set them statically - it doesn't matter how the VMs are addressed) and they also CAN access the corporate network AND the internet as expected.  But nothing can access the VMs, cannot access shares, cannot RDP, cannot ping.  Also, none of the VMs can access other VMs on the same cluster and exhibit the same behavior.

Just so you can grasp the strangeness of this, imagine virtual servers VM1 and VM2 on the cluster, and NONVM1 outside the cluster.  VM1 can access NONVM1, shares, RDP, ping, etc, as expected.  But, even though NONVM1 knows VM1 exists due to DNS resolution only, it cannot access it at all, no shares, no RDP, no ping.  Also, VM1 CANNOT access VM2 on the same cluster and vice versa.

All drivers and firmware are up to date. I have tried and assumed it was VMQ settings, but this does not appear to be the cause.  The Cluster Validation runs and passes everything.

I'm at a total loss to explain this one.

Any ideas, and thank you in advance.
I have a 2012r2 Windows, hyper-V VM running on a dell r320 server that I am going to move it to a dell r720 server.  Can I simply export the VM from the r320 and import it on the r720, change the NIC and fire it up?
We have a 2012 R2 Host Server that had been backing up 100% Using Altaro Software. Now we are getting failed backups. We have found that the "Microsoft Hyper-V VSS Writer" keeps failing. During our investigations we have found that we appear to have a corrupt file (Catsrvut.dll) being part of the COM process we have tried to fix the corruption. The error message is below. If we just run "SFC /SCANNOW" the results say everything is fine but it clearly is not if you runf SCANFILE. Running this command also comes back with a clean report "DISM.exe /Online /Cleanup-image /Restorehealth"

It seems that this file is not easy to fix so we are asking for some assistance to resolve this corruption. Thanks in advance guys.

"C:\Windows\system32>sfc /scanfile=c:\windows\system32\catsrvut.dll

Windows Resource Protection found corrupt files but was unable to fix some
of them. Details are included in the CBS.Log windir\Logs\CBS\CBS.log. For
example C:\Windows\Logs\CBS\CBS.log. Note that logging is currently not
supported in offline servicing scenarios."
Running Hyper V host on a Win 2016 server with 2 VMs that are allowed with the licensing. I need to 'replace' one of my VMs temporarily, as part of my move from 2008 SBS to Exchange 2016 & wonder if it's possible to remove one of my VMs, add another for the hop to exchange 2013, then remove that one when finished & restore (or import) the original one back in?
Hi all,

I am having a serious problem hosting websites based on Redhat or Centos on Hyper-V.  While on physical server that is not the case even when the CPU and memory is much less than what is been allocated for on Hyper-V.

30 - 50 user's try to access a page to upload document or login, the server gets hanged completely.  sometime we have to force restart because we cannot even login to reboot the server.  but that is not the case with physical server even when the memory and CPU is half of what is been used on Hyper-V.

One of the issues I am facing on Hyper-V is the memory releases, which keeps increasing and never get release unless I use a run /bin/sync; /bin/echo 3 > /proc/sys/vm/drop_caches on crontab to release the memory or force restart the server.

I am getting to a point to move all my web onto physical machine due to that problem.  can you please help me resolve that problem.  Is the fix from the Windows, Linux or Apache?
I am using two host computers running Server 16 to setup 4 VM servers for a new domain. Host1 will have VM1 as the domain controller and VM2 as the Exchange Server. Host 2 will have VM3 as the secondary domain controller and VM4 as the file and application server.
Do the host machines need to join the network after the domain controller is up and running? what is the best practice?
Rick Cowperthwaite
Rick's Energy Solutions
Configuration Guide and Best Practices
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Hi everyone,

I have virtualized a Windows 2003 server into an Hyper-V environment with Disk2VHD. In the physical server I am able to do this:
I am able to see the content of netlogon.

When I do that in the virtual system (exact 100% the same Windows / setting / etc. offcourse) I get:
\\servername\netlogon is not accessible. You might not have the right permissions for this network location. Contact system administrator.

I do not get this permissions error since I cloned the physical to virtual, so everything should be exactly the same.

I am looking for the necessary detailed steps to take prior to converting my physical Active Directory Server/Domain Controler to a Hyper-V Virtual Machine.
I want to be able to create my Hyper-V VM , Attach the VHDX, and be up and running as soon as possible in the event of a Server failure.
I have successfully created  bootable Server 2008 and Server 2012 VM's,  but each VM brings up a "Directory Services Restore Mode" prompt prior to allowing me to log into the newly created VM.
I would like to avoid DSRM all together.
Thank you in advance.
I'm running four hyper-v servers hosting about 20 virtual servers and I'm using replication.

Currently, my exchange server is in a critical replication state and the report is that it has not replicated since December 6, 2017!!!

When I right click and resume replication, I get a message that a resent is needed, but when I try that, the merge starts and then goes back to error state.  I DO see a message that reads Last successful replication for virtual machine Exchange has been delayed.  Delay has exceeded the defined critical limit.  Replication might be encountering problems.

What I have done in the past is remove replication and then re-enable it.  I'm tired of that lazy approach but I'm not sure how to go about troubleshooting replication issues in Hyper-V.

Can someone give me a few basic steps to troubleshoot this?


Hi all. I have 2 physical boxes running 2012 R2.

Box one SM GW running VMware workstation with 2 ESXi virtual hosts. Also I have vSphere which has the 2 hosts added to a cluster and then i created a couple of VMs inside the cluster. VMs in the cluster can can ping host and get to the internet.
IP range for VMware workstation is  (please attached image vmip)

Box two IP SM GW running Hyper-V with several VMs including lab DCs. For Hyper-V network pleased see image hvip.

Problem. VMs on box 1 (vmware) can ping and communicate to VMs on box 2. I can even join VMs to the domain whereby they have to communicate with a DC on box 1, the Hyper-V server.

VMs on box 2 however, the Hyper-V guests cannot ping, map drives to VMs on box 1.

There are no firewalls running

I believe the VMs on box 1, the VMware server can ping because the default network has them bound to the physical host card. So the vmware network is taking care of the natting. What i can't figure out is what i have to do the network on the Hyper-V host to make those VMs see the VMs on the VMware host.
Any pointers appreciated.
I had a job to upgrade some VM hardware versions today. all the Hyper-V nodes in the cluster are 2016.

I've upgraded the cluster version from 8 to 9 (that didn't cure my problem).

The highest Host Hardware version available is version 5 (server 2012) Why can't I see version 8?

Im running Get-VMHostSupportedVersion I only see version 5 (set to default)?

Whats been missed, why no version 8

We have a client who we added 4 new domain computers to over the weekend (they had an existing 6 on the domain) to an existing domain control virtual machine running Windows 2012 Standard R2. Ever since the users started working on Monday the files on the server and network shares are opening as "Read-Only". We've checked the shares and they are set to Full Access, we've checked subfolders and they have full access and aren't locked for read only. We have checked for files being open on different workstations causing the issue and all files are closed. This issue did not exist before adding these users and the issue is being experienced by all users (all on Windows 10 pro), those who were on the domain before as well as new users.
Hello Experts,

I have two Hyper-V servers Running Windows 2012 R2. Hyper-V-01 and Hyper-V-02. Hyper-V had a RAID failure and I lost all VM configurations and virtual hard disks. Lost a second RAID disk during a rebuild.

I have gone to Hyper-V-02 and run Repliacation>Failover on each VM so my VM's are UP.  I have replaced the bad drive on Hyper-V-01 and formatted and recreated the VM storage volume.

My question is what are my next steps?  Do I simply go to Hyper-V-02 Replication>Reverse Replication to reverse the failover and move the VM's back to the Primary Hypervisor or are other steps required?  Please be specific as this is my first Hyper-V Replication Failure.
I added  a new 2016 Hyper-V server.  It gets the message (see attached) failed to change state.  

I've added plenty before and never seen this.

How do I fix this?

 change state error
VIDEO0021.mp4The machine is taking quite a while to start up (15 minutes) and once fully booted it freezes. It has six hard drives but as you can see in the attached video only one of them is actively blinking. Until I rebooted the one that is actively blinking was cycling orange and green indicating a predictive failure.
In general I am not sure what the problem can be. I am able to ping all the virtual servers on the machine but I cannot remote into them or see them on the desktop because it is frozen.
What is SQL Server and how does it work?
What is SQL Server and how does it work?

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400TB Disaggregate Cluster
Herein one will find an aggregate of some of my experience building and deploying virtualization stacks both in standalone, clustered Hyper-V, clustered Hyper-V with a Scale-Out File Server (SOFS) backend, and Storage Spaces Direct (S2D).
Please share the process to check hyper-v disk space on core server without logged into the server, as one of our Hyper-v core server is connected via VMM but not able to take RDP.
Hi all,

Just a quick question on a big subject and would like some thoughts...

I have a server I plan to use as a basic Hyper-V host and I don't know how many virtual processors to allocate across the VM's

The Host has two XEON 8 Core Hyperthreaded CPU's and plenty of RAM, I would like to know how many vCPU's that equates to roughly

I plan to run two Exchange servers in a DAG and would like recommendations for how many to allocate each of them? There will also be a number of Server 2016 and 2012R2 machines running various small loads and some Windows 7 and 10 clients.

I have read all sorts of conflicting answers and I'm unsure of what to do.

Thanks for reading and participating in this question.

I have inherited a Windows 2012 R2 Hyper-V cluster.  The hosts are running full GUI Windows.  The hosts are using DAS with SAS interface (To be clear).  On the Hyper-V cluster are 2 Windows 2008 R2 servers in a cluster (Yes an upgrade is on the schedule).  I am having an issue configuring a Quorum disk for the Windows 2008 cluster.  On each of the hosts there is the same LUN connected from the DAS and it is offline.  That disk has been assigned to each of the Windows 2008 R2 servers.  On 1 of the VMs the disk is offline and on the other it is online.  When I go into the cluster manager in Windows 2008 R2 where the disk is online and try to add clustered storage non is found.

Correct me if I am wrong, but if the Quorum LUN from the DAS is not assigned to the hosts then I cannot assign it to the VMs??

What am I doing wrong???

I have 4 node Storage Spaces Direct (S2D) cluster with two adapter. One for serving client and other one is for the Cluster only. In switch it is configured as trunk mode. The primary is serving PROD Vlan subnet and secondary virtual adapter has cluster only but no vlan been set but VLAN been enabled without IP set on the core switch.  In SCVMM 2016 of the virtual machines for the S2D cluster are getting the error as follows. Sometimes we are able to manage sometimes all options are disabled.
Error (13921)
The highly available virtual machine (VM03) is not supported by VMM because one or more of its network adapters is not configured correctly.
Recommended Action
Ensure that all of the virtual network adapters are either disconnected or connected to highly available virtual switches.

The virtual switch is created, is there any document to verify the Virtual Network setup to fix this issue. Perhaps we are missing something or the VLAN gateway should be configured for the secondary adapter on Hosts.

This is annoying and giving big headache. But on other aspect all VM's are communicating and live migration works perfectly.  

Any suggestion and help appreciated.
I had a weird scenario.
after installing some updates and restarting the VM's on hyper V.
i noticed that ALL workstations on a VLAN able to ping each other, All servers on the same VLAN able to ping each other.
all servers and workstations are able to ping each other excel TWO.
two servers couldn't ping any workstations, nor the opposite.
not sure why there two servers only.
we restarted everything, that did no fix the problem.
we restarted the switch, the problem was fixed.
while looking at the logs on the switch, i noticed some duplicate MAC addresses of the same host.
the switch is a cisco switch, i don't have much more to share, and it seems pretty odd, don't know where to start in my troubleshooting. any ideas ? brain storming with me can be helpful.
thank you


Hyper-V is a native hypervisor; it can create virtual machines on x86-64 systems and supersedes Windows Virtual PC as the hardware virtualization component of the client editions of Windows NT. A server computer running Hyper-V can be configured to expose individual virtual machines to one or more networks. Hyper-V Server supports remote access via Remote Desktop Connection. Administration and configuration of the host OS and the guest virtual machines is generally done over the network.