Citizendia
Your Ad Here

For musical recordings, see Live album. A live album &ndash commonly contrasted with a Studio album &ndash is a recording consisting of material (usually music recorded during stage performances
Live CD of ubuntu, running Firefox, OpenOffice.org and Pidgin
Live CD of ubuntu, running Firefox, OpenOffice.org and Pidgin

A Live CD or LiveCD or CD Live Distro is a computer operating system that is executed upon boot, without installation to a hard disk drive. Ubuntu Kubuntu Edubuntu Xubuntu Gobuntu --> Ubuntu OpenOfficeorg ( OOo or OOo) is a free Cross-platform office application suite available for a number of different computer Pidgin (formerly named Gaim) is a multi-platform Instant messaging client. An operating system (commonly abbreviated OS and O/S) is the software component of a Computer system that is responsible for the management and coordination In Computing, booting ( booting up) is a bootstrapping process that starts Operating systems when the user turns on a Computer system A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device Typically, the LiveDistro is named after the bootable medium it is stored on, such as a CD-ROM or DVD (Live CD/DVD) or a USB flash drive (Live USB). CD-ROM (an initialism of "Compact Disc Read-Only Memory " is a pre-pressed Compact Disc that contains data accessible to but not writable DVD (also known as " Digital Versatile Disc " or " Digital Video Disc " - see Etymology)is A live USB or USB live distro is a USB flash drive or an External hard disk drive containing a full Operating system which can be booted

The term "live" derives from the fact that these "distros", or software distributions, each contain a complete, functioning and operational operating system on the distribution medium. A LiveDistro does not alter the operating system or files already installed on the computer hard drive unless instructed to do so. LiveDistros often include mechanisms and utilities for more permanent installation, including disk partitioning tools. Disk partitioning is the creation of separate divisions of a Hard disk drive using Partition editors Once a disk is divided into several partitions directories and The default option, however, is to allow the user to return the computer to its previous state when the LiveDistro is ejected and the computer is rebooted. ReBoot is a Canadian CGI - animated action-adventure Television series that originally aired from 1994 to 2001 It is able to run without permanent installation by placing the files that typically would be stored on a hard drive into RAM, typically in a RAM disk. A RAM disk is a software layer that enables applications to transparently use RAM, often a segment of Main memory, as if it was a Hard disk However, this does cut down on the RAM available to applications, reducing performance somewhat. As of 2007, certain LiveDistros run a graphical user interface in as little as 32MB RAM.

In some LiveDistros, the user can optionally install the OS from the removable media to the hard disk drive (they are called installable LiveDistros).

Contents

History

On computers, optical discs were originally intended for storing video. Then the principles of storing information into the optical disc were changed to provide storing different types of information. In the case of operating systems those were mostly installation files, often packaged and archived in compressed formats. Later, it became convenient and useful to boot the computer from compact disc, often with a minimal working system in order to install a full system onto a hard drive, and troubleshoot hardware. Although early Linux developers and users were able to take advantage of cheap optical disks and rapidly declining prices of CD drives for personal computers, the Linux distribution CDs or "distros" were generally treated as a collection of installation packages that must first be permanently installed to hard disks on the target machine. Linux (commonly pronounced ˈlɪnəks A Linux distribution (also called GNU/Linux by distributions such as Debian, Fedora, Ubuntu, Linux Mint, Mandriva and

The first Compact Disc drives on personal computers were generally much too slow for running complex operating systems such as Linux. Often, the computer could not even boot from optical discs. When operating systems were distributed on discs, either a boot floppy or the CD itself would boot specifically, and only, in order to install onto a hard drive. A boot disk is a removable digital data storage medium from which a Computer can load and run ( boot) an Operating system or utility program There was little reason not to install directly on a hard disk. However, in the case of Linux, the free operating system was meeting resistance in the consumer market because of the difficulty and effort and risk involved with installing an additional partition on the hard disk, particularly the ext2 filesystem. The ext2 or second extended file system is a File system for the Linux kernel. The term "Live CD" was coined because after typical PC RAM was large enough and 52x speed CD drives and CD burners were widespread among PC owners, it finally became convenient and practical to boot the kernel, run X11, a window manager and GUI applications directly from a CD without disturbing the OS (generally Windows on FAT32 or NTFS) on the hard disk. This was a new and different situation for Linux than other OSes, because the updates/upgrades were being released so quickly, different distributions and versions were being offered online, and especially because users were burning their own CDs. Copying Linux from the installation media was also encouraged instead of actively hindered and discouraged with such things as requiring the input of long and elaborate serial numbers and lengthy and complicated installation procedures.

The first Linux-based Live CD was Yggdrasil Linux (went out of production in 1995), though in practice it did not function well due to the low throughput of then-current CD-ROM drives. Linux (commonly pronounced ˈlɪnəks Yggdrasil Linux/GNU/X, or LGX (pronounced igg-drah-sill) was an early Linux distribution developed by Yggdrasil Computing Incorporated Year 1995 ( MCMXCV) was a Common year starting on Sunday. Events of 1995 The Debian-derived Linux distribution Knoppix was released in 2003, and found popularity as both a rescue disk system and as a primary distribution in its own right. Debian ( pronounced) is a computer Operating system composed entirely of Free and open source software. Knoppix, or KNOPPIX (nopɪks is a GNU/Linux Operating system based on Debian designed to be run directly from a CD / DVD Year 2003 ( MMIII) was a Common year starting on Wednesday of the Gregorian calendar. Data recovery is the process of salvaging data from damaged failed corrupted or inaccessible secondary storage media when it cannot be accessed normally Since 2003, the popularity of Live CDs has increased substantially, partly due to Linux Live scripts and remastersys which made it very easy to build customized live systems. Remastersys is a free and Open source script for Linux Ubuntu -based operating systems that can Create a customized Live

Most of the popular Linux distributions now include a Live CD variant, which in some cases is also the preferred installation medium. A Linux distribution (also called GNU/Linux by distributions such as Debian, Fedora, Ubuntu, Linux Mint, Mandriva and

Uses

Some LiveDistros are designed to "demo" or "test drive" a particular operating system (usually Linux or another free or open source operating system). Free software or software libre is Software that can be used studied and modified without restriction and which can be copied and redistributed in modified or unmodified Open source is a development methodology which offers practical accessibility to a product's source (goods and knowledge

Although some live CDs can load into memory in order to free the optical drive for other uses, loading the data off a CD-ROM is still slower than a typical hard drive boot, so this is rarely the default. [1] Experienced users of the operating system may also use a LiveDistro to determine whether and to what extent a particular operating system or version is compatible with a particular hardware configuration and certain peripherals. [1] Users may also use a LiveDistro to troubleshoot hardware, especially when a hard drive fails. Some Live CDs can save user-created files in a Windows partition, a USB drive, a network drive, or other accessible media.

LiveDistros can be used for many purposes, including providing an environment for optionally installing a Linux distribution to a hard drive, testing new versions of software, testing hardware, system repair and restoration, high security/non-invasive environment for a guest, cracking/stealing passwords, network security testing, and as a fall back when a main drive fails. A Linux distribution (also called GNU/Linux by distributions such as Debian, Fedora, Ubuntu, Linux Mint, Mandriva and Everyday use of LiveDistros is rare because CDs are slower than hard drives, because user files in a RAM disk are lost when the power is turned off, and because systems may not have access to a swap disk for opening many large applications.

Mounting without burning

The files on a Live Distro ISO image can be accessed in Microsoft Windows with a disk image emulator such as Daemon Tools, or in Unix variants by mounting a loop device. An ISO image is an Archive file (aka Disk image) of an Optical disc using a conventional ISO ( International Organization for Standardization Microsoft Windows is a series of Software Operating systems and Graphical user interfaces produced by Microsoft. A disk image emulator is Computer software designed to mount a Disk image, usually of a CD or DVD, from a local Hard drive or Daemon Tools (styled DAEMON Tools by its creators is a Disk image emulator and optical disc authoring program for Microsoft Windows. Unix (officially trademarked as UNIX, sometimes also written as Unix with Small caps) is a computer

Common traits

Some LiveDistros come with an installation utility launchable from a desktop icon that can optionally install the system on a hard drive or USB flash drive. A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device Most LiveDistros can access the information on internal and/or external hard drives, diskettes and USB flash drives. A floppy disk is an increasingly Obsolete data storage medium that is composed of a disk of thin flexible ("floppy" Magnetic storage medium encased Generally LiveDistros are booted from read-only media, requiring either copying to rewriteable media (i. e. a hard drive) or complete remastering to install additional software; however, there are exceptions such as Morphix and Puppy Linux which are one of the few Linux Live CD distributions able to save files to the Live CD itself or other multisession medium, allowing users to carry data, and more importantly, added programs and customized settings, along with them on optical disc. Morphix is a modular Operating system, based on Knoppix (which is in turn based on Debian) Puppy Linux is a Live CD Linux distribution that is very small and focuses on Ease of use. Optical disc authoring, including DVD and Blu-ray Disc authoring (often referred to colloquially but improperly as burning) is the process of assembling

Most LiveDistros are based on Linux, as this was the operating system that had the most to gain by offering free trials and demonstrations without regard to sales or copyright. Now others are using the term LiveDistro for other operating systems, such as OpenSolaris, BeleniX and others based on Solaris. OpenSolaris is an Open source project created by Sun Microsystems to build a developer community around Solaris Operating System technology BeleniX is an operating system distribution built using the OpenSolaris source base Solaris is a Unix -based Operating system introduced by Sun Microsystems in 1992 as the successor to SunOS. Other "live" operating systems include ReactOS, NetBSD, FreeBSD, OpenBSD, MINIX 3, Plan 9 from Bell Labs, MorphOS and FreeDOS. ReactOS is a computer Operating system intended to be binary-compatible with Application software and Device drivers made for Microsoft NetBSD is a freely redistributable Open source version of the Unix -derivative Berkeley Software Distribution (BSD Computer Operating FreeBSD is a Unix-like free Operating system descended from AT&T UNIX via the Berkeley Software Distribution (BSD branch through OpenBSD is a Unix-like computer Operating system descended from Berkeley Software Distribution (BSD a Unix derivative developed at the MINIX 3 is a project to create a small highly reliable and functional Unix-like Operating system. Plan 9 from Bell Labs is a Distributed operating system, primarily used for research MorphOS is a computer Operating system (OS It is a mixed proprietary and Open source OS produced for the Pegasos PowerPC (PPC-processor-based FreeDOS (formerly Free-DOS and PD-DOS) is an Operating system for IBM PC compatible computers Although Mac OS and various Microsoft Windows releases can function as "live CDs" they are not referred to as such. Mac OS is the trademarked name for a series of Graphical user interface -based Operating systems developed by Apple Inc Microsoft Windows is a series of Software Operating systems and Graphical user interfaces produced by Microsoft. This may be because these systems are only intended to be run from CD for troubleshooting, repair and installation. There are a growing number of Windows-based utilities like Windows PE, Windows RE and BartPE that resemble and function as LiveDistros, however. Windows Preinstallation Environment (WinPE is a lightweight version of Windows XP, Windows Server 2003 or Windows Vista BartPE (Bart's Preinstalled Environment is a Live CD / Live USB version of the Microsoft Windows XP or Windows Server 2003 32bit The first personal computer operating system on a CD to support "live" operations might have been the AmigaOS, which could be booted from CD on an Amiga CDTV in 1990. AmigaOS is the default native Operating system of the Amiga personal computer . Earlier examples of live OS are of course the operating systems used from floppy, and most widely spread is DOS. DOS, short for "Disk Operating System" is a shorthand term for several closely related Operating systems that dominated the IBM PC compatible market Unlike previous operating systems on optical media, though, Linux "Live CDs" were specifically designed to run without installation onto other media like a hard disk drive. The LiveDistro concept was meant to promote Linux and showcase the abilities of the free, open source operating system on conventional personal computers with Microsoft Windows already installed. Open source is a development methodology which offers practical accessibility to a product's source (goods and knowledge

On a PC, a bootable Compact Disc generally conforms to the El Torito specification. A personal computer ( PC) is any Computer whose original sales price size and capabilities make it useful for individuals and which is intended to be operated The El Torito Bootable CD Specification is an extension to the ISO 9660 CD-ROM specification Many Linux based LiveDistros use a compressed filesystem image, often with the cloop compressed loopback driver, or squashfs compressed filesystem, generally doubling effective storage capacity, although slowing application start up. The compressed loopback device or cloop is a module for the Linux kernel. Squashfs (sfs is a compressed read-only File system for Linux. The resulting environment can be quite rich: typical Knoppix systems include around 1,200 separate software packages. Knoppix, or KNOPPIX (nopɪks is a GNU/Linux Operating system based on Debian designed to be run directly from a CD / DVD LiveDistros have a reputation for supporting advanced auto-configuration and plug-and-play functionality. Auto-configuration is the automatic configuration of devices without manual intervention without any need for software configuration programs or jumpers Ideally Plug-and-play is a computer feature that allows the addition of a new device normally a Peripheral, without requiring reconfiguration or manual installation of Device This out of necessity so as to avoid requiring the user to configure the system each time it boots, and to make them easily usable by those who are new to the operating system.


Technique

A read-only file system, such as on a CD-ROM has the drawback of being unable to save any current working data. In Computing, a file system (often also written as filesystem) is a method for storing and organizing Computer files and the data they contain to make For this reason, a read-only file system is often merged with a temporary writable file system in the form of a RAM disk. A RAM disk is a software layer that enables applications to transparently use RAM, often a segment of Main memory, as if it was a Hard disk Often the default Linux directories "/home" (containing users' personal files and configuration files) and "/var" (containing variable data) are kept in ramdisk, because the system updates them frequently. In Computing, a directory, catalog, folder or drawer is an entity in a File system, which contains a group of files and/or other directories In Computing, configuration files, or config files', are used to configure the initial settings for some Computer programs They are used In Computer science, data is anything in a form suitable for use with a Computer.

In modern LiveDistros, a read-only file system is merged with ramdisk using transparent techniques such as UnionFS or AuFS. Any change in a Computing system such as new feature or new component is transparent if the system after change adheres to previous external interface as much as UnionFS is a filesystem service for Linux and FreeBSD which implements a Union mount for other File systems. In MS-DOS systems, a DOS utility, ramdrive. sys, can be loaded at boot for this purpose.

LiveDistros have to be able to detect a wide variety of hardware (including network cards, graphic cards etc. A Network card, Network Adapter, LAN Adapter or NIC (network interface card is a piece of Computer hardware designed to allow computers A video card, also known as a graphics accelerator card, display adapter, or graphics card, is a hardware component whose function is to ). This is easily achieved nowadays by udev or hotplug, which is a common part of all distributions based on Linux kernel 2. udev is the device manager for the Linux 26 kernel series Primarily it manages Device nodes in /dev. Linux is an operating system kernel used by a family of Unix-like Operating systems These are popularly termed Linux operating systems and 6.

Cheat code

Codes that are introduced during Live CD initialization to change the booting behavior. They vary from distribution to distribution but can most often be accessed upon first boot screen by one of the function keys. A function key is a key on a Computer or terminal keyboard which can be programmed so as to cause an operating system command interpreter or application

See also

References

  1. ^ a b Brickner, David (2005). In Computer science, persistence refers to the characteristic of data that outlives the execution of the program that created it Remastersys is a free and Open source script for Linux Ubuntu -based operating systems that can Create a customized Live SystemRescueCD is an Operating system which runs from a bootable CD-ROM disc (a Live CD) or a USB flash drive, useful for repairing Virtual CloneDrive is a Disk image emulator. It is specially designed to mount images created by the SlySoft program CloneCD, although it can mount Test Driving Linux: From Windows to Linux in 60 Seconds. O'Reilly. ISBN 059600754X.  

External links

© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org
 Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic