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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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We have 4 domain controllers. Three are running on hyper-v virtual machines and one is physical. I want to get rid of the physical AD server, but keep getting a file replication error on it. This one server is the only one with this error and it is the only service getting an error on the machine. The event viewer id numbers for the error are 13552 and 13555. Since I want to get rid of this server any way, can I just demote it, remove AD, then shut it down or do I need to resolve the file replication issue first?

Thank you
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Is it possible to live migrate storage from one hyper-v cluster to another? (different SAN)

Windows Server 2016

Hi All,
I have a Hyper-V server replicating to another server with a single VM on it which works fine so
Server1 ----VM1---- Server2

I have added another VM to Server1  which I would like to replicate to Server3 while keeping the replication between Server1 and Server2 so.

Server1 ----VM1---- Server2

All three hosts are 2012 R2 both VM's are 2012 R2.

Is this possible because at the moment I'm struggling or can a host only replicate to one server?


John H
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?
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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?
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.
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.
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 have msa 2040 san storage with 5 servers with hyper-v role that are connected to fiber san switch.
i plan to get veeam backup solution to backup my servers  on other 2040 san storage
do i have to install veeam on dedicated server ?
do i have to connect backup san storage to san switch ?
do i have to install any other product of veeam on my server ? "i am plan to get veeam backup and replication"
i have 5 servers hp dl380 g9 that is working with ms windows 2012 r2 and hyper-v
i plan to move all vhd files to hp msa 2040 san storage.
regarding my reading the scenario will be:
server 1 fiber channel 1 will connect to switch 1 on port 3
server 2 fiber channel 1 will connect to switch 1  on port 4
server 3 fiber channel 1 will connect to switch 1  on port 5
server 4 fiber channel 1 will connect to switch 1  on port 6
server 5 fiber channel 1 will connect to switch 1  on port 7
server 1 fiber channel 2 will connect to switch 2 on port 3  
server 2 fiber channel 2 will connect to switch 2 on port 4
server 3 fiber channel 2 will connect to switch 2 on port 5
server 4 fiber channel 2 will connect to switch 2 on port 6
server 5  fiber channel 2 will connect to switch 2 on port 7  
San Fiber 1 Connect To Switch 1 port 8 "Controller 1"
San Fiber 2 Connect To Switch 1 port 9 "Controller 1"
San Fiber 3 Connect To Switch 1 port 10 "Controller 1"
San Fiber 4 Connect To Switch 1 port 11 "Controller 1"
San Fiber 1 Connect To Switch 2 port 8 "Controller 2"
San Fiber 2 Connect To Switch 2 port 9 "Controller 2"
San Fiber 3 Connect To Switch 2 port 10 "Controller 2"
San Fiber 4 Connect To Switch 2port 11 "Controller 2"
in this case the acquirement hardware part number are:
Storagex1 : hp 2040 k2r79a
Server Cardx5: HPE SN1000q 16gb 2p FC HBA
Switchx2 :
HPE SN6000B 16Gb 48-port/48-port Active Power Pack+ Fibre Channel Switch
Cable:x18 HPE OM3 …
I am using windows server 2012 R2.
on this host, a guest OS of Windows XP SP 3 is installed to access Sybase adaptive DB services.
when I am accessing it in the same location it works fine. but dies when accessing remotely from VPN connection.
already disabled Hyper V queuing and assigned static MAC address too.

Please suggest if you know any solution.

we purchase Veeam backup and replication 9.x .I installed on the physical server running on window server 2016 .This server also configured as hyper-v manager and deploy 2 vmguest for different application.

now I need to setup disaster recovery ,let said this server hardware failure .We can use Veeam to perform the bare metal recovery to another hardware.

Please advice how to setup above..

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I suddenly was denied to log in to my Hyper-V host from the Hyper-V management console.

I get the error message (translated from my language):  "RPC server is unavailable.  Cannot establish communication between HYPERHOST.mydomain.local and MMC-computer."

Which puzzles me is that I can connect to HYPERHOST's remote desktop with the same credentials...

How can I get the Hyper-V MMC connection up and running again?

Thanks a bunch for help on this.

On the Hyper-V host (Pic 1 and Pic 2), we have a volume called “Volume2” containing 4 x 4TB HDs (mirrored) -- so the total capacity is about 7.27 TB. This volume2 provides for nothing but the VM file server “BUD” – with the following two VHDX files:

Bud.vhdx (2012R2 OS) :     about 52.35GB of max 80GB (dynamic)
Bud_Data.vhdx (for Data): about  4.49TB  of max 7.27TB (dynamic)

So we can do a math and figure the free space of Volume2 is roughly about 2.67TB as shown on Pic 1.
But if we go into the VM’s drive properties and Disk Management, we can see the free space of that drive is about 4.58TB.  That is a huge difference. Can you please educate me why and what could be wrong?
I have a dynamically expanding virtual server. The VHDX file is 400gb but the actual space used on the machine is only 100gb.. i had cleaned up the server and removed 100's of gb worth of data. My question is how do i now get my VHDX file back down to a smaller size?

Srv 2016
Hyper V
I want to install sage 300 2012 ERP  and later want to use this server to host the company's (which I work) website
there are 8 SAS HDD 1.2TB , I configured the first 2 HDDs as RAID 1, the rest (HDD 3,4,5,6,7,8) as RAID6.

I installed Windows server 2012 R2 DC on a physical hp proliant dl380 Gen8 ( IP, gateway my router, dns , no DHCP server installed on the server, the DHCP already configured in the router) ,installED AD DC & DNS roles.
then created the first hyper-v VM (windows server 2012 R2 Standard) as a database server for installing SQL server 2014.(IP, GATEWAY, DNS
after that I get an error when I try join this hyper-v guest to the host (which is WS 2012  R2 DC running on the physical server)

My questions please:
- Is that good configuration??
- I'm using routerboard to control bandwidth at the company that is why I am using DHCP on my router.
- I can ping the guest PC from the server but cannot ping the server from the host
- I created a virtual switch named "db2k12std" and linked it to the database hyper-v machine ,which NIC should I configure? the one which appears in the operating system running on the hyper-v machine? or the NIC that appeares at the networks adapters on the host operating system  (the vEthernet db2k12std is available there).
- there is another IP address (autoconfiguration IPv4) although I assign a manual IP address to my guest , tried to disable …
My users use Accuterm for telnet connections to a Linux server database. The emulation settings are determined by a specific IP address or mac address for each user. Is it OK to create a virtual nic for each user so that they will have their own ip and mac address for their connection to the same VM? There are only about 5 users who need to connect this way. I'm sure there are other ways to deal with this issue, but I wan't sure if having multiple nics on one vm would cause issues. Any thoughts?
We have a client that has 30 users on qbooks 2017 enterprise. they are running on a new dell server in hyper-v and using RDS. This environment has been running for 10+ years without an issue (other than quickbooks sucking). windows 10 dell pc's. the file runs well for a while then an error comes upthe error we get when quickbooks goes unresponsive. no one can get back in after this. we've had the file rebuilt thinking it was the file and it worked for 8 hours. intuit has been no help can't get a competent tech. watchgaurd firewall, cisco poe switch. backups using replibit device. we really need quickbooks high level tech expertise. we have a dba, programmer and two techs on the tshoot.

the file fails even from the console.

we tested on multiple stand alone pc's off the network and the file fails

we put the file on the hyper v host and attached local quickbooks installed pc's to it and it failed. (taking out rds).

the failure is not predictable happens 7 hours in, then may go another 1hr then 30 minutes, etc.

our log shows no discernible trend.


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.