[SOLVED] Hyper-Threading vs No Hyper-Threading; Fixed vs Variable Memory

Feb 18, 2016
8
2
23
37
Hi. I have a question for Proxmox 4.4.

There is the option "Ballooning" which is available with the option "Use fixed size memory". In the help manual says :

Even when using a fixed memory size, the ballooning device gets added to the VM, because it delivers useful information such as how much memory the guest really uses. In general, you should leave ballooning enabled, but if you want to disable it (e.g. for debugging purposes), simply uncheck Ballooning.

I'm configuring a Windows server 2012 VM. I want to have a fixed size memmory, but I'm confused about this option. Should I enable it?
 
Apr 6, 2012
144
14
38
So it appears no one has said anything about this so I'll make a comment. If more people can back this up, even better.
I turned off memory ballooning on all VMs on our weakest node. After doing so, those VMs had performance like what they'd have on the stronger nodes. This may seem anecdotal but I used the recommendation and came up with better performance. It certainly would seem that the recommendations from 2014 are still valid.
 

sdet00

Active Member
Nov 18, 2017
44
13
28
So it appears no one has said anything about this so I'll make a comment. If more people can back this up, even better.
I turned off memory ballooning on all VMs on our weakest node. After doing so, those VMs had performance like what they'd have on the stronger nodes. This may seem anecdotal but I used the recommendation and came up with better performance. It certainly would seem that the recommendations from 2014 are still valid.
Interesting findings. Do you have more information on how the performance was improved? What % difference are we talking?
 
Apr 6, 2012
144
14
38
Honestly, I know everyone always wants to see some sort of metric but without context, that would be no better than standard anecdotal evidence. I've now taken all of our KVM VMs off of ballooning and they are all noticeably faster. I know this is anecdotal and perceptual but believe you me, that matters greatly to our customers and therefore to us. We use RDP to sign in through the cloud to all these servers and the sign in is now twice as fast as it was. As far as metrics, I'd say the ones originally posted to this thread years ago would probably still be valid from the performance increase I'm feeling.
 
Apr 6, 2012
144
14
38
Perhaps some helpful numbers ..
We have a Dell Server with dual 18 core processors that normally runs at a CPU load of 18 to 22 at this time of the morning (8:40am EST) and right now is only running at 14
We have a couple of other Dell servers with dual 12 core processors that usually run at about 12 to 14 on CPU load at this time of the morning that right now are only running 5 and 7
Significant return of CPU power back to the hardware and nothing else changed except getting rid of the ballooning
 

sdet00

Active Member
Nov 18, 2017
44
13
28
Thanks for the info. If I ever get some time I might do some testing myself, so far I haven't really seen a difference.
 

thiagotgc

Member
Dec 17, 2019
126
12
23
35
Is the correct deactivation with the balloon=0 option?

This feature is so interesting, but if it really consumes so much resource, it becomes unfeasible.
 

macpip

Member
Oct 9, 2019
13
8
8
30
As @thiagotgc asked, for Windows guest VMs is it sufficient to set balloon=0 on the host ?
This way on the VMs I don't see anymore the Virtio Ballon Driver in Device Manager, but the Balloon Service is still running.
Do I need to stop/disable the Balloon Service or furthermore uninstall it inside the VM?
Is the correct deactivation with the balloon=0 option?

This feature is so interesting, but if it really consumes so much resource, it becomes unfeasible.
 
Last edited:
  • Like
Reactions: thiagotgc

About

The Proxmox community has been around for many years and offers help and support for Proxmox VE, Proxmox Backup Server, and Proxmox Mail Gateway.
We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get your own in 60 seconds.

Buy now!