Overview

snf-image-creator is a simple command-line tool for creating OS images. The original media, the image is created from, can be:

  • a block device, representing a hard disk
  • a disk image file, representing a hard disk (supports all image file formats supported by QEMU)
  • the host system itself

Snapshotting

snf-image-creator works on snapshots. Any changes made by the program do not affect the original media.

Image Preparation

During the image creation, a number of system preparation operations are applied on the media snapshot. Some of those are OS specific. snf-image-creator will use heuristics to detect the OS and determine which operations to apply. Those operations will:

  • Shrink the image
  • Clear out sensitive user data (passwords, ssh keys, history files, etc.)
  • Prepare the guest OS for being deployed on a virtual environment (change device names, remove persistent net rules, install VirtIO drivers, etc.)

Creation

The program can either dump the image file locally or use ./kamaki to directly upload and register it on a Synnefo deployment as private or public image.

Image Format

The extracted images are in diskdump format, which is a raw dump of a disk device (or file). This is the recommended format for snf-image, the Ganeti OS Definition used by Synnefo.