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LiveCD


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Description

A LiveCD is an operating system (that usually contains other software as well) stored on a bootable CD-ROM that can be executed from it, without installation on a hard drive. The system returns to its previous OS when the LiveCD is ejected and the computer is rebooted.

Some LiveCDs come with an installation utility launchable from a desktop icon that can optionally install the system on a hard drive or USB keydrive. Most LiveCDs can use a ready CD or burn an ISO image downloaded from the internet. Because of the large size of the image files many people use a download manager for this.

Some LiveCDs come with an installation utility launchable from a desktop icon that can optionally install the system on a hard drive or USB keydrive. Most LiveCDs can access the information on internal and/or external harddrives, diskettes and USB Flash memories (i.e. to store data -home directory- or to be used like rescue systems).

For example, in Dynebolic the nest file is called dynebol.nst and it keeps all your home and settings inside (/home, /etc, /var, /tmp). The available space for your nest is found by dyne:bolic through your partitions on hard drive or USB storage devices (like USB pens, smartcards or even photo cameras). This approach doesn't require any change in the data structure of the partitions: just one file is created (dynebol.nst).

Most LiveCDs contain a system based on the Linux kernel, but there are also LiveCDs for other operating systems, like FreeBSD or Microsoft Windows (but most of the latter can't be distribued freely, so they must be built with uttilities such as bart-pe) or testing os such as reactOS , ununium or others. The first OS to support LiveCD operations appears to have been BeOS, which could be brought to a full desktop from a CD-ROM as far back as R3, in 1998.

The syslinux utility is used to boot most LiveCDs as well as Linux floppies. On a PC a bootable CD generally conforms to the El Torito specification which treats a special file on the disc (possibly hidden) as a floppy diskette image. Many Linux LiveCDs use a compressed filesystem image (often with the cloop compressed loopback driver,but others exist such as squashfs).

Some livecd support the instalation of programs with the help of unionfs(a kernel module) that permit to merge a read-only filesystem(here the cloop(or other) file on the cd) into a read-write filesystem,so here it install the program on the ram,so they disapears at reboot

The common solution here is to use a loop file stored on the hard disk or into a removable media in order to save changes to the configurations,add programs,files permanantly

This article has been written by: [User:Whoever Wrote This]

See Also

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Last modified: Sun, 13 May 2007 06:55:00 +0000 Hits: 21,811