Creating and Managing Linux Virtual Machines with KVM

Introduction

Virtualization technology has revolutionized the way we deploy and manage servers. It allows us to create multiple virtual machines (VMs) on a single physical server, thereby maximizing resource utilization and enhancing flexibility. Kernel-based Virtual Machine (KVM) is an open-source virtualization solution for Linux that enables users to create and manage VMs efficiently. In this blog post, we will explore the process of creating and managing Linux VMs using KVM.

Prerequisites

Before proceeding, make sure you have the following requirements in place:

A Linux server running a supported distribution (such as CentOS or Ubuntu).
Sufficient CPU, memory, and storage resources on the server.
Administrative privileges or root access to the server.

Installing KVM

To begin, we need to install KVM on our Linux server. The installation process varies depending on the Linux distribution you are using. Here, we will provide a general overview of the steps involved:

Update your package manager:

$ sudo apt update      (For Ubuntu)
$ sudo yum update      (For CentOS)

Install KVM hypervisor and related packages:

$ sudo apt install qemu-kvm libvirt-daemon-system libvirt-clients      (For Ubuntu)
$ sudo yum install qemu-kvm libvirt libvirt-client                    (For CentOS)

Add your user to the libvirt group:
```
$ sudo usermod -aG libvirt $USER
```
Restart the system to apply the changes.

Creating a Virtual Machine

Now that KVM is installed, we can proceed with creating a Linux VM. Follow the steps below:

Download a Linux distribution ISO file or use an existing one.
Launch the Virtual Machine Manager (Virt-Manager) application:
```
$ virt-manager
```
Click on "New VM" to start the new VM creation wizard.
Choose the installation method and provide the path to the Linux ISO file.
Specify the amount of memory and storage for the VM.
Customize the hardware settings like CPU cores, network connections, and display options.
Finish the wizard, and the VM will be created.

Managing Virtual Machines

Once the VM is created, you can manage it using Virt-Manager or command-line tools. Here are some common management tasks:

Starting and Stopping a VM:

$ virsh start <vm-name>
$ virsh shutdown <vm-name>

Monitoring VM Status:

$ virsh list       (View the list of running VMs)
$ virsh dominfo <vm-name>     (Get detailed information about a VM)

Accessing VM Console:
```
$ virt-viewer <vm-name>
```

Taking Snapshots:

$ virsh snapshot-create-as <vm-name> <snapshot-name>

Restoring from a Snapshot:

$ virsh snapshot-revert <vm-name> <snapshot-name>

These are just a few examples, and there are many other advanced management operations possible with KVM.

Conclusion

Kernel-based Virtual Machine (KVM) provides a robust and flexible virtualization solution for Linux enthusiasts. With KVM, you can effortlessly create and manage Linux VMs, maximizing resource utilization and enhancing system efficiency. Whether it's for development, testing, or production environments, KVM is a versatile tool that empowers users to take full advantage of virtualization technology.

本文来自极简博客，作者：蓝色幻想，转载请注明原文链接：Creating and Managing Linux Virtual Machines with KVM