Summary
In this chapter, we went through the performance tuning aspects of a KVM setup. Starting with the virtio framework, we went through various subsystems, such as CPU and memory, disk and block I/O, network time keeping, and tuning possibilities. We also covered NUMA concepts, Hugepages, KSM, and the tuning that can be applied with it. Performance has to be measured and you have to come up with the best options to match your scenario.
In the next chapter, we will discuss how to migrate your virtual machines running on foreign hypervisors to the KVM hypervisor using the virt-v2v
tool. We will also discuss physical machine-to-virtual machine migration in the next chapter.