Windows VM High Memory Consumption and Host Memory Reporting Discrepancy

[Nitin Patil]

We are observing a memory utilization discrepancy for a Windows VM running on Proxmox VE.

The memory usage reported at the Proxmox host/VM level is significantly higher than the actual memory utilization observed inside the Windows VM, even when the VM is idle with minimal workload.

We have properly installed the required VirtIO drivers and configured the QEMU Guest Agent. The VM IP address is correctly reflected in the Proxmox VM Summary confirming that guest-agent communication is working.

However, the memory utilization discrepancy still persists.

Impact

This is affecting host memory capacity planning. The memory reported as consumed by the Windows VM is being considered as part of the host's memory utilization, which reduces the available memory shown on the Proxmox host.

As a result, the available memory for creating additional VMs appears lower than the actual memory available, which may impact or restrict new VM creation and resource allocation.

Support Required

Please help us determine why the Proxmox host is reporting higher memory consumption for this Windows VM and whether this is expected behavior.

Please confirm whether the behavior is related to:

• Windows memory caching/standby memory
• Proxmox memory accounting
• VirtIO Ballooning
• QEMU memory allocation
• Windows VirtIO Balloon driver
• QEMU Guest Agent
• Any specific Proxmox configuration required for accurate memory reporting and efficient host memory utilization

We would also like to understand the recommended configuration so that unused memory from the Windows VM can be appropriately managed/reclaimed by Proxmox and accurately reflected in the host's available memory for additional VM deployments.

 

[janus57]

Hi,

you should show image/number of what your are seeing.

99% of the time what the host see is what windows is trying to consume.

Best regards,

 

[Nitin Patil]

Hii,

Please see attachment.

 

[janus57]

Hi,

you nedd to tell more about your VM configuration and host status

Best regards,

 

[_gabriel]

Memory usage of Guest, reported once Guest Agent VirtIO Balloon driver/service is installed, is memory used from point of view of the guests not from point of view of the host.
Cached memory in the Guest is really reserved on the host, cannot be shared.
This metric helps to decrease or increase reserved memory for the guest. Start with low assigned memory then increase if memory usage is high.
(sorry for my non native English wording....)

 

[Impact]

Memory is not reported via the Guest Agent. Give this a look: https://gist.github.com/Impact123/3...bcaab9e3#why-is-my-vms-memory-usage-incorrect
Can you share a picture of your VM's Hardware tab, your node's Summary and your VM's windows Task Manager?
Please also explain what you expect it to show.