Welcome to CernVM Virtual Machine documentation!

What is the CernVM Virtual Machine?

CernVM is a virtual machine image based on CentOS combined with a custom, virtualization-friendly Linux kernel.

CernVM is based on the µCernVM bootloader. Its outstanding feature is that it does not require a hard disk image to be distributed (hence “micro”). Instead it is distributed as a read-only image of ~20MB containing a Linux kernel and the CernVM-FS client. The rest of the operating system is downloaded and cached on demand by CernVM-FS. The virtual machine still requires a hard disk as a persistent cache, but this hard disk is initially empty and can be created instantaneously.

Contents

• Release Notes
  • CernVM 4.5 [27.01.2021]
  • CernVM 4.4 [17.06.2020]
  • CernVM 4.3 [27.01.2020]
  • CernVM 4.2 [04.02.2019]
  • CernVM 4.1 [12.06.2018]
• How to run on…
  • VirtualBox
  • KVM
  • CernVM as a Docker Container
  • OpenStack
  • Amazon EC2
  • Google Compute Engine
  • Microsoft Azure
• CernVM Launch
  • Installation
• Contextualization
  • Introduction
  • Contextualization of the µCernVM Boot Loader
  • Contextualization with amiconfig
  • Contextualization with cloud-init
  • Mixing user-data for µCernVM, amiconfig, and cloud-init
  • glideinWMS User Data
  • Extra Contextualization
  • Applying User Data
• Micro-CernVM Bootloader
• CernVM Image Signatures

Contact and Authors

Visit our website on cernvm.cern.ch.

Authors of this documentation:

• Jakob Blomer