Windows VM Swap

Shadow Sysop

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Mar 7, 2021
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I've done allot of research on this but can't find any answers that are satisfying. I want to see what the Proxmox community thinks.

I am currently running multiple identical nodes (AMD Epyc 7351, DDR4 2400 RAM, SATA HDD). The bottleneck is the HDD, but we have to make them work. I noticed a Windows VM was causing allot of IO delay, as it was close to exhausted the allocated RAM so was obviously swapping allot. I disabled swap in this VM, and the IO delay has returned to normal, though the RAM is dangerously close to it's max of 8GB (it flexes around 7.6GB...little lower and little higher here and there). Even though it's not happened yet, I fear a BSOD due to Out of Memory....but with the SWAP off, the IO delays are way less.

I'm thinking off running all my future Windows VMs without swap, to prevent these nasty IO delays. Can anyone chime in with some thoughts? Please note.

I can't switch to SSDs (don't suggest, I know they're better. server can not be reconfigured.)
 
I'm thinking off running all my future Windows VMs without swap, to prevent these nasty IO delays. Can anyone chime in with some thoughts? Please note.
How did you do it? I thought running Windows without a pagefile is impossible?

What about other optimizations e.g. disabling hibernate, running optimizations like ShutUp to disable services and therefore logging to disk.
 
In order to disable the pagefile in Windows 10, you have to access the Virtual Memory settings. Follow these steps:

Right-click on This PC icon on your desktop, and then select Properties.

Once you get to the window, click on the “Advanced system settings” link on the left.
advanced-system-settings

In the System Properties window, select the Advanced tab, and then click the Settings button under the Performance section.

Select the Advanced tab and then click the Change button under the Virtual memory section.

Disable page file.
 
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In order to disable the pagefile in Windows 10, you have to access the Virtual Memory settings. Follow these steps:

Right-click on This PC icon on your desktop, and then select Properties.

Once you get to the window, click on the “Advanced system settings” link on the left.
advanced-system-settings

In the System Properties window, select the Advanced tab, and then click the Settings button under the Performance section.

Select the Advanced tab and then click the Change button under the Virtual memory section.

Disable page file.
Thank you for explaining.

What about the other things liks optimizing the services, energy settings, hibernation, etc.? Have you don'e something there?
 
Power settings don't make appreciable difference in VMs in my testing and experience. Just to note, they are all disabled anyway.

It's mainly just an issue of preventing excessive write/read ops on HDDs. Swap is the biggest culprit here.
 
In one of out installation we use small enterprise class SSD (or NVME) in each server to store VMs swap. Each VM (Windows) uses common shared storage (NFS) for system and data disks and local store (ext4) for additional (swap) disk.
 
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This is a great idea but unfortunately I can not reconfigure the servers in anyway. Best I could o would be SSD via NAS
 

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