Overview
Welcome to our comprehensive KVM (Kernel-based Virtual Machine) tutorial, where we explore the world of virtualization using the powerful open-source virtualization technology provided by the Linux kernel. KVM offers a robust and efficient platform for running multiple virtual machines (VMs) on Linux-based systems.
What You’ll Learn
In this tutorial, we cover the following key aspects of KVM:
Introduction to KVM: Gain a solid understanding of the fundamentals of virtualization and the role of KVM in Linux. Learn about the architecture of KVM, its integration with the Linux kernel, and the advantages it offers in terms of performance, scalability, and resource utilization. Understand the difference between full virtualization and paravirtualization.
KVM Installation and Configuration: Follow step-by-step instructions to install and configure KVM on your Linux system. Learn how to check hardware virtualization support, enable kernel modules, and configure necessary system settings. Understand the requirements for running KVM, including hardware compatibility, kernel versions, and software dependencies.
Creating and Managing Virtual Machines: Discover how to create and manage virtual machines using KVM. Learn about different disk formats and storage options available in KVM, including QEMU images and direct storage access. Understand how to allocate CPU and memory resources to virtual machines. Explore techniques for managing virtual networks and connecting VMs to the host and external networks.
VirtIO and Device Management: Learn about VirtIO, a paravirtualization interface for KVM that provides efficient I/O operations between the host and guest VMs. Understand how to configure VirtIO drivers for improved performance and better integration between the host and guest systems. Explore device management in KVM, including adding and removing virtual devices and configuring device passthrough for direct access to host hardware.
Networking and Storage in KVM: Dive into networking and storage configuration in KVM. Learn how to set up virtual networks and bridges to enable communication between VMs and external networks. Understand network addressing and packet filtering using tools like iptables. Explore storage management, including using disk images and managing storage pools for efficient VM storage.
Live Migration and High Availability: Discover advanced features of KVM, such as live migration and high availability. Learn how to migrate running VMs between hosts without downtime using technologies like KVM-QEMU live migration and shared storage. Understand how to configure high availability for VMs using tools like Pacemaker and Corosync, ensuring continuous operation even in the event of host failures.
Performance Optimization and Monitoring: Explore techniques for optimizing performance in KVM. Learn about CPU pinning and memory ballooning for improved resource allocation. Understand how to monitor VM performance using tools like libvirt, virt-top, and Grafana. Explore best practices for optimizing storage and network performance in KVM environments.
KVM Security and Compliance: Learn about security measures and compliance in KVM. Understand how to secure VMs and the host environment by implementing firewalls, access controls, and encryption. Explore techniques for auditing and monitoring KVM environments to ensure compliance with security standards and regulations.
Throughout this tutorial, we provide practical examples, command-line snippets, and configuration files to help you become proficient in KVM virtualization. We aim to empower you with the knowledge and skills to effectively deploy, manage, and optimize virtualized environments using KVM.
By the end of this tutorial, you will have a comprehensive understanding of KVM and its capabilities, enabling you to confidently leverage its power to create and manage virtual machines in your Linux-based infrastructure.
Chapters
Chapter 1 : Linux Virtualization, KVM, and Installing KVM Hypervisor
In this section, you will learn about different types of virtualization, hypervisor types, and Linux virtualization concepts (Xen and KVM).
You will also learn of virtualization concepts and the need to virtualize our environments, explains the basic hardware and software aspects of virtualization, and the various approaches to virtualization.
You will also learn new concepts including oVirt, a GUI that can be used to manage our virtualized Linux infrastructure. We take you through the process of checking whether the hardware used is compatible with KVM, introduce some basic commands for virtual machine deployment, and then move on to explain how we’d use oVirt in the same scenario.
| Topics | Read Time |
|---|---|
| Introduction to Virtualization on Linux | |
| Overview of KVM (Kernel-based Virtual Machine) | |
| Installing KVM on Various Linux Distributions | |
| Initial Configuration of KVM Environment |
Chapter 2 : Libvirt Networking
In this section you will learn how libvirt interacts with various networking concepts – virtual switches in different modes, how to use CLI tools to manage libvirt networking, TAP and TUN devices, Linux bridging, and Open vSwitch.
After that, You will get more extreme examples of networking by using SR-IOV, a concept that should get us the lowest latency and highest throughput and is used in cases where every single millisecond counts.
| Topics | Read Time |
|---|---|
| Basics of Libvirt Networking | |
| Configuring Network Bridges | |
| Setting Up NAT and Routed Networks | |
| Advanced Networking Concepts |
Chapter 3 : Libvirt Storage
In this section you will learn about Libvirt Storage, as storage concepts are extremely important when building virtualized and cloud environments.
You will know every type of storage that KVM supports – local storage pools, NFS, iSCSI, SAN, Ceph, Gluster, multipathing and redundancy, virtual disk types, and so on.
| Topics | Read Time |
|---|---|
| Understanding Libvirt Storage Options | |
| Setting Up and Managing Storage Pools | |
| Creating and Managing Storage Volumes |
Chapter 4 : Virtual Display Devices and Protocols
In this section you will learn about various virtual machine display types, remote protocols including VNC and Spice, as well as NoVNC, which ensures display portability as we can use a virtual machine console inside a web browser by using NoVNC.
| Topics | Read Time |
|---|---|
| Overview of Virtual Display Technologies | |
| Configuring and Securing Remote Access | |
| Performance Tuning and Troubleshooting |
Chapter 5 : Virtual Machines
In this section you will learn to Virtual Machines Installation, Configuration, and Life Cycle Management, introduces additional ways of deploying and configuring KVM virtual machines, as well as migration processes, which are very important for any kind of production environment.
| Topics | Read Time |
|---|---|
| Creating Your First Virtual Machine | |
| Managing VMs with virsh and Virt-Manager | |
| Snapshots and Cloning VMs |
Chapter 6 : Creating and Modifying VM Disks
In this section you will learn to Create and Modify VM Disks, Templates, and Snapshots, various virtual machine image types, virtual machine templating processes, the use of snapshots, and some of the use cases and best practices while using snapshots.
| Topics | Read Time |
|---|---|
| Disk Image Formats and Their Uses | |
| Resizing and Managing Disk Images | |
| Advanced Disk Management |
Chapter 7 : Customize a Virtual Machine with cloud-init
In this section you will learn one of the most fundamental concepts in cloud environments – how to customize a virtual machine image/template post-boot.
Cloud-init is used in almost all of the cloud environments to do post-boot Linux virtual machine configuration, and you will know how it works and how to make it work in your environment.
| Topics | Read Time |
|---|---|
| Introduction to cloud-init | |
| Automating VM Customization with cloud-init | |
| Troubleshooting and Best Practices |
Chapter 8 : Automated Windows Guest Deployment and Customization
In this section you will learn Windows Guest Deployment and Customization, with a razor-sharp focus on Microsoft Windows virtual machine templatization and post-boot customization.
For that, you should use cloudbase-init, a concept that’s basically the same as cloud-init, but which is suited for Microsoft-based operating systems only.
| Topics | Read Time |
|---|---|
| Installing Windows on KVM | |
| Automating Windows Deployments | |
| Customizing Windows VMs |
Chapter 9 : Ansible and Scripting for Orchestration and Automation
In this section you will learn to deploy AWX and Ansible, and how to use these concepts in your KVM-based environments.
This is just one of the Ansible usage models that is employed in modern-day IT, as the whole DevOps and infrastructure-as-a-code story gets much more exposure in IT infrastructure all over the world.
| Topics | Read Time |
|---|---|
| Introduction to Ansible for KVM | |
| Writing Ansible Playbooks for VM Management | |
| Scripting for Automation |
Chapter 10 : Scaling Out KVM with OpenStack, and AWS
In this section you will learn to the process of building cloud environments based on KVM. OpenStack is the standard approach to delivering just that when using KVM.
In this section, you will learn about all of the OpenStack building blocks and services, how to deploy it from scratch, and describe how to use it in production environments.
You will also learn about public and hybrid cloud concepts by using Amazon Web Services (AWS).
| Topics | Read Time |
|---|---|
| Integrating KVM with OpenStack | |
| Using KVM with AWS | |
| Large-Scale Virtualization Strategies |
Chapter 11 : KVM Virtualization Platform Monitoring and Performance tunning
In this section you will learn a very popular concept of monitoring via the Elasticsearch, Logstash, Kibana (ELK) stack.
It also takes you through the whole process of setting up and integrating the ELK stack with your KVM infrastructure, all the way through to the end result – using dashboards and UIs to monitor your KVM-based environment.
You will also learn about various approaches to tuning and optimization in KVM-based environments by deconstructing all of the infrastructure design principles and putting them to (correct) use. We cover a number of advanced topics here – NUMA, KSM, CPU and memory performance, CPU pinning, the tuning of VirtIO, and block and network devices.
| Topics | Read Time |
|---|---|
| Monitoring KVM Environments | |
| Performance Tuning of KVM Hosts and Guests | |
| Troubleshooting Common Issues |
FAQs (Frequently Asked Questions)
What is KVM (Kernel-based Virtual Machine)?
KVM is an open-source virtualization technology built into Linux that allows you to turn Linux into a hypervisor that hosts multiple, isolated virtual environments or machines.
Who should use KVM?
KVM is suitable for anyone looking to implement virtualization solutions, ranging from IT professionals and system administrators to developers and students interested in virtualization technologies.
What are the prerequisites for using KVM?
A Linux system (preferably a recent version), hardware that supports virtualization extensions (Intel VT or AMD-V), and sufficient system resources (CPU, memory, storage) to host multiple VMs.
Is KVM free to use?
Yes, KVM is open-source and free to use. It’s part of the Linux kernel.
How does KVM compare to other virtualization solutions like VMware and Hyper-V?
KVM offers a more integrated and native experience on Linux systems and is open-source, while VMware and Hyper-V are proprietary solutions with different feature sets and licensing models.
What operating systems can be run on KVM virtual machines?
KVM supports a wide range of guest operating systems including Linux, Windows, MacOS, and BSD.
How do I install KVM on my system?
Installation steps vary depending on the Linux distribution, but generally involve installing the qemu-kvm, libvirt, and virt-manager packages, and enabling the virtualization extensions in the BIOS.
What is the difference between QEMU and KVM?
QEMU is a generic and open-source machine emulator and virtualizer, while KVM is a specific technology that extends QEMU’s capabilities by using hardware virtualization features.
Can KVM be used for production environments?
Yes, KVM is widely used in production environments due to its stability, scalability, and performance.
How does networking work in KVM?
KVM supports various networking modes, including bridged, NAT, and private networking, to connect virtual machines to the outside network and to each other.
Can I migrate VMs from other hypervisors to KVM?
Yes, it is possible to migrate VMs from other hypervisors like VMware and Hyper-V to KVM, but the process may require conversion tools and careful planning.
How do I manage KVM virtual machines?
Virtual machines in KVM can be managed through command-line tools like virsh, or graphical interfaces like virt-manager.
What is libvirt in KVM?
Libvirt is an open-source API, daemon, and management tool for managing platform virtualization, including KVM.
Are there any best practices for using KVM?
Best practices include regular backups, monitoring performance and resource usage, and keeping the KVM host and guest systems updated and secure.
Where can I find more resources to learn about KVM?
Official KVM documentation, Linux distribution forums, virtualization technology blogs, and online courses are great resources for learning more about KVM.
