Live image

From Gentoo Wiki
Jump to:navigation Jump to:search
Resources

A live image provides an operating system (OS) environment contained within a file that can be used to boot a system. Live images are typically written to local media to be used to boot into a "live environment". Such an environment is often non-persistent, but can sometimes be used to install a "permanent" OS to non-volatile storage.

Live images are used to create a live environment from which to install Gentoo to persistent storage. Live images may also be used to maintain a Gentoo-based operating system, particularly in the case of issues resulting in a non-bootable system.

Gentoo offers the LiveGUI USB Image, the Minimal Installation CD, and an Admin CD.

A live image can also be called a LiveUSB image, or live operating system image. Historically, a live image has been referred to as a "LiveCD", "LiveDVD", "ISO file", "LiveUSB GUI", etc.

Important
A live image file isn't commonly used "as is" to boot physical hardware: images should not usually just be "placed" on a disk as a file with a "copy" command, but rather "interpreted as an entire disk", with the aid of specialized software. See the LiveUSB article for more information.

Live images offered by Gentoo

The Gentoo release engineering project produces live images for installation of or maintenance to Gentoo-based operating systems.

Go to the bootable media article to see what live images are offered by Gentoo for download.

What live images are used for

Live images are used for a variety of useful purposes such as:

  • Installation of a Linux or other operating system
  • Demoing features prior to installation
  • System rescue
    • Failed disk drive hardware
    • Failed or corrupted file system
    • Corrupted or missing kernel binary or modules preventing normal use of the system. In particular when missing a network interface driver or a filesystem required to mount rootfs
  • Digital forensics
  • Development
    • Kernel driver development
  • "Portable installation"
  • Accessing/controlling physical hardware resources with an unlocked bootloader without needing special credentials for login :)
  • Testing
    • Hardware testing
    • Software testing

Format

It is typical for live images to be image files created in the ISO 9660 (ECMA-119) file system format using either El Torito or Joliet extensions and represented by an .ISO file extension.

Gentoo live images are hybrid, meaning the image can either be burned to optical media or directly written to a USB drive using a data dump tool such as dd.

See also

  • Bootable media — Gentoo offers bootable media that can be used to install, maintain, or try out Gentoo Linux
  • Installation — an overview of the principles and practices of installing Gentoo on a running system.
  • Live environment — a term that describes an ethereal or disposable operating system environment, typically created from a live image.
  • LiveUSB — explains how to create a Gentoo LiveUSB or, in other words, how to emulate a x86 or amd64 Gentoo LiveCD using a USB drive.
  • Stage file — an archive containing a minimal Gentoo environment, typically serving as a seed for a Gentoo install.

External resources