Install of Server 2025 using high amount of resources
- Thread starter Keith Miller
- Start date
May you can consider install virtio drivers for windows into this VM and check how actually memory usage?
https://pve.proxmox.com/wiki/Windows_VirtIO_Drivers
https://pve.proxmox.com/wiki/Windows_VirtIO_Drivers
There's a best practice guide for running Server25 on Proxmox: https://pve.proxmox.com/wiki/Windows_2025_guest_best_practices
I'd recommend starting there. That being said, Server25 isn't exactly the leanest on resources
I'd recommend starting there. That being said, Server25 isn't exactly the leanest on resources
Why should it? Dozens of Domain-Controllers with 2025 running here with just 2 Cores and 4Gig RAM.... nothing to worry about.... it all depends on what you want to use it for.... What always helps, having fast disks....
Possibly if it is basically idling - like a domain controller that is not much more than a telephone book. (Show me that VM status image when you are doing a major update!).
But the OP has given his 32 GiB of ram - seems like he intends to use it properly, don't see that happening with 2 cores. I agree that centric to this discussion the OP should give more info on the workload.
For Windows Server 2025 you should use OVMF (UEFI) instead of SeaBIOS, the Machine type should be q35
Caution, switching from BIOS to UEFI after install may make the VM unbootable
2 vCores = 1 physical Core, that is not much, i would at least assign 4 vCores = 2 physical Cores to a Windows VM, more is always better
Caution, switching from BIOS to UEFI after install may make the VM unbootable
2 vCores = 1 physical Core, that is not much, i would at least assign 4 vCores = 2 physical Cores to a Windows VM, more is always better
I increased core to 4 and memory back to 32gig Max and 30Gig min with ballooning checked
It was unbootable, is there anything I can do to fix that other than revert to SeaBIOSFor Windows Server 2025 you should use OVMF (UEFI) instead of SeaBIOS, the Machine type should be q35
Caution, switching from BIOS to UEFI after install may make the VM unbootable
2 vCores = 1 physical Core, that is not much, i would at least assign 4 vCores = 2 physical Cores to a Windows VM, more is always better
i read somwhere in the forum that memory ballooning for windows vm's could be a culprit for bad performance and stability issues - so i would rather disable it
there are ways to switch a windows install from bios to uefi but i would recommend to reinstall and let windows do it's partitioning, tinkering around with a windows server vm in that way is not beneficial for stability
there are ways to switch a windows install from bios to uefi but i would recommend to reinstall and let windows do it's partitioning, tinkering around with a windows server vm in that way is not beneficial for stability
Ballooning must be enable to get VM RAM inside usage and hide red memory usage.
This allow to fine allocate VM RAM.
But indeed, for Windows guest, set same Min RAM and Max RAM as Windows can't release unused RAM to host.
Ballooning is working in Windows guests as well. As long as the ballooning service is installed and running.
Sorry, for my language.
it depends what is expected from Ballooning.
Ballooning inside VM works indeed.
But I don't see the benefit for the host as unused RAM can't be used for the host itself or other guests.
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iirc, once Windows VM consume RAM, qemu process doesn't "trim" / "recover" unused RAM for Windows VM.
I haven't retested since I set same Min/Max RAM for Windows then KSM helps a lot.
I think pictures are better than words:
My little old test machine:
Fresh installed Windows 11 and doesn't do anything at this moment:
You can see, Windows consumes more than 7GB memory and there is nothing running.
In same pic If you click eject Balloon Driver you can see this:
And this in Windows:
Just as a little explanation what ballooning is doing.
My little old test machine:
Fresh installed Windows 11 and doesn't do anything at this moment:
You can see, Windows consumes more than 7GB memory and there is nothing running.
In same pic If you click eject Balloon Driver you can see this:
And this in Windows:
Just as a little explanation what ballooning is doing.
it's just the "reporting"/"view" of RAM used within VM.
And it's important to report within VM usage to fine-tune the VM RAM size.
Check your host RAM usage.
And it's important to report within VM usage to fine-tune the VM RAM size.
Check your host RAM usage.
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