Book Image

Mastering KVM Virtualization

Book Image

Mastering KVM Virtualization

Overview of this book

A robust datacenter is essential for any organization – but you don’t want to waste resources. With KVM you can virtualize your datacenter, transforming a Linux operating system into a powerful hypervisor that allows you to manage multiple OS with minimal fuss. This book doesn’t just show you how to virtualize with KVM – it shows you how to do it well. Written to make you an expert on KVM, you’ll learn to manage the three essential pillars of scalability, performance and security – as well as some useful integrations with cloud services such as OpenStack. From the fundamentals of setting up a standalone KVM virtualization platform, and the best tools to harness it effectively, including virt-manager, and kimchi-project, everything you do is built around making KVM work for you in the real-world, helping you to interact and customize it as you need it. With further guidance on performance optimization for Microsoft Windows and RHEL virtual machines, as well as proven strategies for backup and disaster recovery, you’ll can be confident that your virtualized data center is working for your organization – not hampering it. Finally, the book will empower you to unlock the full potential of cloud through KVM. Migrating your physical machines to the cloud can be challenging, but once you’ve mastered KVM, it’s a little easie.
Table of Contents (22 chapters)
Mastering KVM Virtualization
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Working with memory


Memory is a precious resource for most environments, isn't it? Thus, the efficient use of memory should be achieved by tuning it. The first rule in optimizing KVM memory performance is not to allocate more resources to a guest during setup than it will use!

We will discuss the following in greater detail:

  • Memory allocation

  • Memory tuning

  • Memory backing

Memory allocation

Let us start by how to allocate memory for a virtual system or guest. To make the allocation process simple, we will consider the libvirt client virt-manager again. Memory allocation can be done from the window shown in the following screenshot.

Figure 15: Memory allocation window

As you can see in the preceding figure, there are two main options: Current allocation and Maximum allocation:

  • Maximum allocation: The runtime maximum memory allocation of the guest. This is the maximum memory that can be allocated to the guest when it's running

  • Current allocation: The actual allocation of memory for the guest. This...