KVM Prerequisites & Pre-Checks

Before installing and using KVM, it's essential to ensure your system meets the necessary requirements and to perform some preliminary checks.

Hardware and Software Requirements

To run KVM, your host machine must have the following:

  • A processor with virtualization support. This means an Intel processor with Intel Virtualization Technology (VT-x) or an AMD processor with AMD-V support. These extensions provide the hardware-level instructions needed to run virtual machines efficiently.
  • A Linux operating system with a minimum kernel version of 2.6.20. KVM was first integrated into the mainline Linux kernel with this version.
  • Superuser (root) privileges. Administrative access is required to install KVM packages and manage the hypervisor and its virtual machines.
  • An ISO image or installation media for the guest operating system. You will need this to install an OS onto your new virtual machine.

Pre-Installation Checks

Perform these checks from the command line to verify that your system is ready.

1. Verify Processor Virtualization Support

First, confirm that the processor virtualization extensions are enabled in your system's BIOS/UEFI. Then, run the following command to check if the CPU flags are visible to the operating system:

# grep -E 'svm|vmx' /proc/cpuinfo
  • vmx (Virtual Machine eXtensions) in the output indicates an Intel processor with virtualization support.
  • svm (Secure Virtual Machine) in the output indicates an AMD processor with virtualization support.

If this command produces no output, you may need to enable the virtualization settings in your computer's BIOS or UEFI.

2. Check Kernel Version

You can see the kernel version to ensure it is 2.6.20 or higher with this command:

# uname -a

This command prints detailed system information, including the kernel version, which will confirm if your OS is compatible.

3. Update Your System

Ensure your host system is up to date with the latest security patches and software updates. On Debian-based systems like Ubuntu, you can use:

# apt update

Keeping your system updated is a crucial security practice and ensures you have the latest stable packages for KVM and its dependencies. For other distributions like CentOS or Fedora, you would use yum update or dnf update.