Hello Everyone,

I have created two windows virtual machines with KVM and set them to have a memory allocation of 1GB and a maximum of 6GB but when I start them up they take all 6GB of ram right away. Also once I go back and look at the details the memory allocation has changed from 1GB to 6GB. Is this supposed to happen and is there a way to stop it?

I looked in the config file for one of the virutal machines and it still says the correct memory settings.

Also this does not happen with any of the linux virtual machines I am running.


Regards

Hi
Doesn't this depend on the baloon driver being available in the guestOS/VM?
http://www.linux-kvm.com/content/bal...gpl-repository

Windows always reserves all the RAM it can find for itself on boot, there's nothing strange about it. If you have KSM enabled, it will easily deduplicate those zero-filled memory pages, and free up the RAM

From what I have read ballooning is a manual process. I could be wrong though....

I did try running KSM and setting up ksmtuned after I started this thread but it doesn't seem to work properly, or I haven't configured it properly. When I start KSM it runs and reduces the ram usage but then turns off and the ram climbs back up. Is KSM supposed to turn off after it has run?

Yes, KSM consumes a lot of resources, so you don't want it running ALL the time, normally you'd want it to start when your RAM usage hits a high percent mark (say 90%), do it's thing, free up all the RAM it can, and turn off until the next time you fill up all your RAM.

Balooning is a totally different approach, normally not in use bu qemu, because KSM is more efficient.