Live USB

A live USB of Ubuntu, running Firefox, OpenOffice.org and the Nautilus file manager.

A live USB is a USB flash drive or a USB external hard disk drive which contains a full operating system that can be booted. Live USBs are closely related to live CDs, but can sometimes persistently save settings, and can permanently install software packages back onto the USB device. Like live CDs, live USBs can be used in embedded systems for

Many operating systems including Mac OS 9, Mac OS X, Microsoft Windows XP Embedded and many of the Linux and BSD distributions can be used from a USB flash drive. Windows 8 can run from a USB drive, with Windows To Go.

History

Since 1999, Apple Macintosh computers (beginning with the Power Mac G4 with AGP graphics and the slot-loading iMac G3 models)[1] have been able to boot from USB. Intel-based Macs support booting Mac OS X from USB.

Specialized USB-based booting was proposed by IBM in 2004, in the papers "Reincarnating PCs with Portable SoulPads" (PDF & Summary) and Boot GNU/Linux from a FireWire device.[2]

Benefits and limitations

Live USBs share many of the benefits and limitations of live CDs.

Benefits

Limitations

Setup

Various applications exist to create live USBs; examples include the WinToUSB (Windows focused), WiNToBootic (Windows focused) or Fedora Live USB Creator and UNetbootin and MultiSystem LiveUSB MultiBoot, which works with a variety of distributions. A few Linux distributions and live CDs have ready-made scripts which perform the steps below automatically. In addition, on Knoppix and Ubuntu extra applications can be installed, and a persistent file system can be used to store changes. A base install ranges between as little as 40 MB to as much as 1 GB.

To set up a live USB system for commodity PC hardware, the following steps need to be done:

Knoppix live CDs have a utility that, on boot, allows users to declare their intent to write the operating system's file structures either temporarily, to a RAM disk, or permanently, on disk and flash media to preserve any added configurations and security updates. This can be easier than re-creating the USB system but may be moot since many current (circa 2010) live USB tools are simple to use.

Full Installation

An alternative to a live solution is a traditional operating system installation with the elimination of swap partitions. This installation has the advantage of being efficient for the software, as a live installation would still contain software removed from the persistent file due to the operating systems installer still being included with the media. However, a full installation is not without disadvantages; due to the additional write cycles that occur on a full installation, the life of the flash drive may be slightly reduced. To mitigate this, some live systems are designed to store changes in RAM until the user powers down the system, which then writes such changes. Another factor is if the speed of the storage device is destitute; performance can be comparable to legacy computers even on machines with modern parts if the flash drive transfers such speeds. One way to solve this is to use a USB hard drive, as they generally give better performance than flash drives regardless of the connector.

Windows

Although many live USBs rely on booting an open-source operating system such as Linux, it is possible to create live USBs for Windows by using Diskpart or WinToUSB.[8]

Examples of Live USB operating systems

Bootable Windows To Go USB flash drive

Comparison

Distribution Alternatives to live CD creation File saving Application saving Boot methods
Fedora 9 Netinstaller (downloads an ISO image and makes USB), UNetbootin In folder None
Gobolinux Zip + sh and bat scripts N/A N/A 2ram (gobolinux toram)
sidux USB installer GUI In folder, on USB stick Auto Normal
Slax Zip + sh and bat scripts, UNetbootin N/A N/A
SliTaz None and from internal drive ($tazusb) In hacker folder Through script (Tazusb) 2ram – lowram
(K,L,X)Ubuntu UNetbootin Auto Auto
Wolvix None (Control Panel) Auto after making permanent space (Control panel) Auto AllUsb – 2Ram

Syslinux is a program that makes a USB storage device bootable (they are often used after extracting files to the formatted media).

See also

External links

Wikimedia Commons has media related to Live USB.
Wikibooks has a book on the topic of: Live distro and Full Linux Install

References

  1. http://support.apple.com/kb/TA25908 Legacy Apple article about USB features in Macs with AGP graphics
  2. "IBM brains capture a PC's soul". CNET. CBS Interactive.
  3. Boot From a USB Drive Even if your BIOS Won’t Let You (How-To Geek)
  4. Plop Boot Manager (Plop)
  5. http://www.pendrivelinux.com/2007/11/21/use-a-floppy-to-boot-usb-pendrive-linux/ boot floppy for live USB
  6. "MactelSupportTeam/EFI-Boot-Mactel". ubuntu.com.
  7. "Linux Mint Forums". linuxmint.com.
  8. Whitson Gordon. "How to Run a Portable Version of Windows from a USB Drive". Lifehacker. Gawker Media.
  9. "404 Not Found". sun.com.
  10. "14 – Disk Setup". openbsd.org.
  11. "Create a MiniMe 2008 USB Flash Drive from Windows". pendrivelinux.com.
  12. Install guide for Puppy Linux and other distros
  13. Secure Hardware Browser is a (bootable read-only bastion host created to protect users while accessing online banking)
This article is issued from Wikipedia - version of the Friday, January 15, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.