Balooning Setup Questions

[infinityM]

Hey Guys,

So i've been reading up on balooning a bit, and I'm a bit confused though.
We have Windows servers setup which need to have 120GB RAM but they only use about 40GB currently.
So I'd like to clear up this RAM. But I can only find guides for setting up the balooning during install. How can one set it up after the fact?

Then also, Is there a down side to balooning?
Does it slow down servers or something of the like?

Thanks in advance

 

[mira]

Take a look at the following Wiki entry, it explains how to install VirtIO drivers in Windows: https://pve.proxmox.com/wiki/Windows_VirtIO_Drivers

The downside to Ballooning is, you can easily overcommit RAM which can result in VM crashes and more if the VMs decide to use more RAM than you physically have. Ballooning only starts once your host reaches ~80% memory usage.

 

[infinityM]

Hey bud,

So first of all thank you, That guide was better than the ones I found since the ISO actually was there .
The only problem I have though, I setup the guest agent and the virtio balooning drivers etc. I can ping the agent too so it looks like it's working, but if I check the parent server resources being used, I can see the server still uses 130GB ram where on the VM itself it only uses 8GB and the balooning is set to 16GB min.

So it's still just using the max. Any idea why it would happen?

 

[Roy360]

Hey bud,

So first of all thank you, That guide was better than the ones I found since the ISO actually was there .
The only problem I have though, I setup the guest agent and the virtio balooning drivers etc. I can ping the agent too so it looks like it's working, but if I check the parent server resources being used, I can see the server still uses 130GB ram where on the VM itself it only uses 8GB and the balooning is set to 16GB min.

So it's still just using the max. Any idea why it would happen?

Are you using passthrough?

https://forum.proxmox.com/threads/windows-10-vm-ballooning-almost-100-ram-usage.55928/page-2

 

[mira]

It will only start ballooning when there is a memory usage of 80% or above on the host.

 

[infinityM]

It will only start ballooning when there is a memory usage of 80% or above on the host.

Do you mean it will only decrease the memory on the VM if the parent NODE's memory usage is 80%?
Or do you mean if the VM reaches 80% it will increase the memory allocated?

 

[mira]

Once the PVE host reaches 80% memory usage, it will start reducing the actual memory used in the VMs that have ballooning enabled.

 

[infinityM]

I thought it starts at the minimum and scales up... That makes more sense thank you . Anyway to test it without having the memory maxed out?