Windows 10 VM slows down network for rest of system

[gowg]

Hello everyone,

 

I have a Windows 10 VM running network video recorder software (Blue Iris) and it's receiving 450 mbit/sec at all times. I have a usenet client in a docker on the same unraid system and its speeds are awful (72mbit/sec) but when I pause the VM, speeds go back to normal (430 mbit/sec).

 

At first glance, this seems to be a network issue, but I have a bare-metal Windows computer hooked up to the same switch, and when I run the usenet client on it, I can get full speed (430 mbit/sec) on usenet as well as 450 mbit/sec on the VM with the NVR. I have gigabit on the unraid box, it's a ryzen 3600 with an x570 asus motherboard and 32gb of RAM.

 

I thought it might be the cache drive not being fast enough, but I did a benchmark and its random write was over a gigabit/sec so that can't be it.

 

Is this some sort of wacky undetectable overhead in the VM's network stack? Would it help to assign the VM its own physical pci-e ethernet adapter? Is there some driver issue that could cause this? I'm using the redhat virtio driver.

[trurl]

8 minutes ago, gowg said:

cache drive not being fast enough,

You don't specifically mention writing to cached shares with the VM or usenet client. Shares are not cached by default.

[gowg]

5 minutes ago, trurl said:

You don't specifically mention writing to cached shares with the VM or usenet client. Shares are not cached by default.

Good point. I just checked and my VM vdisk is in the "domains" share which is on "prefer" cache and it just always stays there as long as the cache is not full, correct? And my Windows 10 VM and its NVR software only use the vidsk in domains except for once a week when the NVR offloads some files to the array.

 

And the usenet client uses a share that I've made that is cache: "yes" so it uses cache. Thanks for your help, these are important details that I missed

Edited April 5, 2021 by gowg

[gowg]

I'm working around this issue, I've decided. I briefly considered throwing a faster m.2 ssd in there, and a discrete ethernet adapter to skirt any driver/bridging issues but It turned out to be close to the cost of a used SFF 8th-gen intel 16gb/128gb ssd computer, so I'm just solving this issue by giving up on the VM and running my NVR on bare-metal. And I get to use quicksync, so my power usage will be way down. The VM was using 50-70% off my 6-core ryzen 3600.