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Best way of reserving memory for Windows 10 host

    Question

  • Question
    What is the best way of reserving enough memory for the host when running Hyper-V on Windows 10?

    Details
    I have a development machine running Visual Studio, Office and some other applications needed for my work.

    Om this development machine I am also using Hyper-V to host a couple of guest machines. Some of these guest are kind of greedy when it comes to memory consumption (SQl Server, Exchange Server) and practically tries to take all available memory for themselves, while still asking for more. This is not an issue among the guests, where Hyper-V distribute the memory well according to the memory prioritizations of the different guests.

    I want to avoid limiting the amount of memory available to a guest, since it vary a lot depending on which guests are currently running.

    The problem is the host, which is left with whatever memory might be left after the guest takes what the can/need.

    I know of the registry setting, MemoryReserve, where you can specify some kind of reserve for the host. Everything I read regarding this setting, tell me not to use it.

    I'm kind of looking for a setting that would enable me to treat the host just as a guest machine when it comes to memory.
    That is, I would, if possible, like to set memory priority for the host, as well as minimum and maximum memory.

    So, does anyone know of a good way to manage the memory of a Windows 10 Ent. Hyper-V host?

    Friday, March 17, 2017 6:27 PM

All replies

  • So, does anyone know of a good way to manage the memory of a Windows 10 Ent. Hyper-V host?

    Probably not a fixed setting you can apply. Some good info here.

    https://msdn.microsoft.com/en-us/library/windows/hardware/dn567657(v=vs.85).aspx

     

     



    Regards, Dave Patrick ....
    Microsoft Certified Professional
    Microsoft MVP [Windows Server] Datacenter Management

    Disclaimer: This posting is provided "AS IS" with no warranties or guarantees, and confers no rights.

    • Proposed as answer by Leo HanModerator Wednesday, March 29, 2017 2:17 AM
    • Unproposed as answer by ThereIsNoName Wednesday, March 29, 2017 8:37 AM
    Friday, March 17, 2017 6:55 PM
  • Why wouldn't you limit RAM to your VMs?  Too much RAM in a VM will usually reduce performance.  

    You have to put some RAM limit in your VM when you create it...why not a reasonable amount?

    • Proposed as answer by Leo HanModerator Wednesday, March 29, 2017 2:17 AM
    • Unproposed as answer by ThereIsNoName Wednesday, March 29, 2017 8:37 AM
    Friday, March 17, 2017 7:00 PM
  • Why wouldn't you limit RAM to your VMs?  Too much RAM in a VM will usually reduce performance.  

    You have to put some RAM limit in your VM when you create it...why not a reasonable amount?

    So you really think that to much memory is the problem here?
    Friday, March 17, 2017 7:02 PM
  • I think the point is that you are in total control of the amount of RAM that you assign to the VMs.  For example, you can create each of the VMs with a maximum memory of 4 GB.  If you have a 12 GB host, that leaves about 4 GB for the host.  Memory on the host is a fixed quantity.  You are in control.  Do not allocate more to the VMs so that it starves the host.  If you do not have enough memory to satisfy the host as well as the VMs, get more memory, or live with the poor performance someplace.

    tim

    Friday, March 17, 2017 11:08 PM
  • I think the point is that you are in total control of the amount of RAM that you assign to the VMs.  For example, you can create each of the VMs with a maximum memory of 4 GB.  If you have a 12 GB host, that leaves about 4 GB for the host.  Memory on the host is a fixed quantity.  You are in control.  Do not allocate more to the VMs so that it starves the host.  If you do not have enough memory to satisfy the host as well as the VMs, get more memory, or live with the poor performance someplace.


    tim


    Ohh, you mean using the obvious way that unavoidable lead to the problems I'm trying to find a better solution to?

    Friday, March 17, 2017 11:28 PM
  • There is no magic involved.  Memory is a fixed resource.  If you want the host to have a reserved amount of memory, you have to ensure the VMs are never allocated memory that would cause them to go over what you want the host to have.  In other words, there is no 'host reserved' parameter.

    tim

    • Proposed as answer by Leo HanModerator Wednesday, March 29, 2017 2:17 AM
    • Unproposed as answer by ThereIsNoName Wednesday, March 29, 2017 8:36 AM
    Friday, March 17, 2017 11:34 PM
  • Hi,
    Are there any updates on the issue?
    You could mark the reply as answer if it is helpful.
    Best Regards,
    Leo

    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Wednesday, March 29, 2017 2:17 AM
    Moderator