Hyper-V dynamic memory not working Windows 10

Nicci Ninow 1 Reputation point
2020-08-17T02:28:13.673+00:00

My VM is not changing it's memory allocation, even though I have dynamic memory enabled. Any ideas?

  • Host is Windows 10 Pro Insider Preview build 20190, up-to-date
  • Guest is Windows 10 Enterprise Evaluation build 19041, up-to-date

From what I can tell, Windows 10 should sort out the integration services itself and dynamic memory should work. There shouldn't be anything special required to make it work. Maybe it's because the Guest is an earlier version of Windows. Ideally I'd like to be able to get it to work these versions.

Disclaimer: I am new to Hyper-V.

Hyper-V
Hyper-V
A Windows technology providing a hypervisor-based virtualization solution enabling customers to consolidate workloads onto a single server.
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  1. Ian Xue (Shanghai Wicresoft Co., Ltd.) 29,651 Reputation points Microsoft Vendor
    2020-08-17T08:51:03.837+00:00

    Hi,

    Is your host physical or virtual? How do you set the memory of the VM?
    Please also check Memory Demand and Memory Status for the selected VM in the info pane at the bottom of Hyper-V manager.
    17849-2020-08-17-164236.png

    Please refer to this link for more details
    https://learn.microsoft.com/zh-cn/archive/blogs/chrisavis/monitoring-dynamic-memory-in-windows-server-hyper-v-2012

    Best Regards,
    Ian

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  2. TimCerling(ret) 1,156 Reputation points
    2020-08-17T12:56:28.83+00:00

    What are you expecting to see? What do you have configured as the startup memory for the VM? Is the VM performing anything that would require the VM to go beyond the size of the startup memory?

    With a single VM, there is often no need for the size of virtual memory to change, particularly if you have the initial size of the memory large enough to handle the contents of the running VM. Dynamic virtual memory is most useful when multiple VMs are running and requesting more memory than what is available on the host. When the host reaches a point of not being able to allocate the memory to a VM that is being requested, it will look to other VMs to harvest unused or least used memory by trimming them through the other VMs' normal memory management. If there is no memory pressure on the system, you may not see any adjustment on the VMs' memory sizes.

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  3. Nicci Ninow 1 Reputation point
    2020-08-17T22:44:35.543+00:00

    @Ian Xue (Shanghai Wicresoft Co., Ltd.)

    Thank you for your reply! The link explains things very well, especially the monitoring aspect which I'd like to implement.

    It's a physical host - my laptop. I'm using the VM as a development environment.

    I set the memory of the VM in the settings.

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    @TimCerling(ret)

    I expected to see the memory allocation to adjust itself post-startup. Initially I had too little memory allocated, expecting the dynamic memory component to scale up after startup. It did not. Then I tried allocating too much memory, expecting it to scale down. It did not - doesn't seem to scale at all.

    At the moment it is one machine, yes. I am hosting on my laptop want to be able to prioritise the work I am doing on this host over the guest.

    18093-image.png