Re: [ovirt-users] what does memory balloon optimize means in cluster?

Hi, Memory ballooning is a technique that allows taking memory from one running VM when the VM is not actively using it and "returning" it when the VM needs it. oVirt uses it when: - ballooning it is enabled in cluster - memory overcommit is enabled for cluster - ballooning device is present in VM (it is by default) - host's memory load gets above 80% We are deliberately pretty slow in changing the available memory so it works best for VMs where the memory consumption does not show sudden jumps. As a summary: Memory ballooning is a technique that allows memory overcommiting a host (overselling if you want). I did a presentation couple of years back about it: https://www.youtube.com/watch?v=PRYo1uOniFo Best regards -- Martin Sivak SLA / oVirt On Wed, Oct 11, 2017 at 3:13 PM, pengyixiang <yxpengi386(a)163.com&gt; wrote: