Live CD

A live CD, live DVD, or live disc is a CD or DVD containing a bootable computer operating system. Live CDs are unique in that they have the ability to run a complete, modern operating system on a computer lacking mutable secondary storage, such as a hard disk drive. Live USB flash drives are similar to live CDs, but often have the added functionality of automatically and transparently writing changes back to their bootable medium. Also, the solid-state device pure electronic operation gives a significant speed advantage by eliminating the CD reader's intrinsic mechanical latencies. Write-locked Live SD WORM systems are the direct solid-state counterpart to live CD's and can be booted natively in a media card slot or by using a USB adapter. Write-locked Live SD systems avoid excessive write cycles or corruption by ill-conditioned software, like viruses, which can prematurely "ruin" a live USB.

The term "live" derives from the fact that these CDs each contain a complete functioning operating system on the distribution medium.

While a live CD typically does not alter any operating system or files already installed on a computer's secondary storage (such as hard disk drives), many live CDs include mechanisms and utilities for altering the host computer's data stores, including installation of an operating system. This is important for the system management aspect of live CDs, such as removing malware, drive imaging, and system recovery.

The default option, however, is to allow the user to return the computer to its previous state when the live CD is ejected and the computer is rebooted. 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, though this does cut down on the RAM available to applications.

Mounting without burning

The files on a live CD 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. After mounting the live CD's filesystem, software on the live CD can be run directly (I.e., without booting) by chrooting into the live CD's mounted filesystem. A live CD ISO image can also be mounted by Virtual Machine software such as VirtualBox and VMware Workstation,POWER ISO or can be converted to a Live USB using SYSLINUX. Tools such as UNetbootin can automate this process.

FAVOURITE LIVE CD'S

• Hiren's Boot Cd
• Ubuntu Boot Cd
• Mandriva Boot Cd
• Fedora Boot Cd
• Ultimate Boot Cd