Extreme slow performance in Windows 2008 R2 Hyper-V


  • Guest OS : Windows 2008 Ent

    Usage : Print Server

    vCPU - 4, 8GB Ram

    Almost always 90% CPU usage & make all print service slow...anyone know why ?

    18 mai 2010 16:11

Toate mesajele

  • I am assuming tha tyour 90% CPU use is within the VM.

    One thing I would try is 'right sizing' your VM.

    Rarely does a VM need more than 2 vCPUs. and rarely does it need 8Gb of RAM.  Adding more and more to a VM does not always give better preformance, it can frequently give worse performance.

    Print Servers are an interesting animal, mainly from the standpoint that they can saturate a network connection and rarely use CPU.

    In your case you have high CPU.  So something is clearly not right.  Unless your print server is also running some service such as PDF conversion which is high CPU - and frequently single threaded.

    Are you only serving print shares?

    Are you running any document converters and presenting them as printers?

    Have you checked that the Integration Components in the VM match the host?  In your case, they don't match if you did not upgrade the ICs in the VM - it will work but in a compatibility mode.

    What is the service in the VM that is causing the CPU spike?

    All the standard rules of Windows troubleshooting still apply.


    Brian Ehlert (hopefully you have found this useful)
    18 mai 2010 17:31
  • Hi Brian,

    The VM only do the print server, no other document converters and presenting them as printers.

    How to check Integration Components ?I build the VM within the 2008 R2

    Moreover, when I install a new printer driver (let's say HP Universal Driver), it costs me over 30 min. or more.



    8 iunie 2010 09:38
  • Print Servers are notorious for two things - CPU spiking and network flooding.

    You built the VM with on Hyper-V R2 - the VM is Server 2008. 

    By default this VM should 'just work' - however you won't have a great experience unless you go through the actions of upgrading the Integration Components within the VM to the R2 level.  By this I mean: during the VM installation process, did you install the Integration Services into the VM?  If you did not consiously do this, then you are running in a compatibility mode and that could be causing your problems.

    Also, did you attempt different configurations of your VM virtual hardware to see if it affected performance? 




    Brian Ehlert (hopefully you have found this useful)
    8 iunie 2010 15:54
  • You could try shutting down the VM, edit the hardware config and remove the network adapter from the VM and replace it with a Synthetic NIC.  By default it uses a "legacy" nic that has poorer performance but allows PXE booting.  You shouldn't need that on a print server.  Keep in mind that you will need to configure the new NIC in the guest OS after you reboot it so jot down your IP address info first.
    MrShannon | TechNuggets Blog | Concurrency Blogs
    11 iunie 2010 12:08
  • Actually, here is the interesting part.

    If you create a VM with Hyper-V manager you get a Synthetic NIC by default; if you create a VM using SCVMM you get a Legacy NIC by default.

    With a print server, as MrShannon mentioned, this will have a major impact as a print server sends a great deal of data.

    Brian Ehlert (hopefully you have found this useful)
    11 iunie 2010 13:23
  • Hi,

    can  you use performance monitor to identified which is causing the problem. Refer to here http://msdn.microsoft.com/en-us/library/cc768535(BTS.10).aspx to give you an idea of which is the root cause problem

    18 iunie 2010 14:11
  • +1

    don't forget to mention the brilliant articles from "tvoellm" around the general Hyper-V performance and the correct usage of perfmon in combination with Hyper-V.




    24 iunie 2010 19:34