KVM Forum 2015

What happens when instead of 10 virtual machines per host system you start 100 or even 1000? What happens when you have 1000 disks per guest? On the Mainframe, setups with hundreds or thousands of devices and a huge number of guests are not unheard of. Large scenarios like that tend to find limiting factors, and that is no different on KVM. In this talk, we will present our findings for such setups under KVM. We will discuss our experiences when trying to scale to large numbers of guests and devices on z Systems: which limits we hit, how we got around them, and where we still have unresolved issues.