Without Free Live Operating System CD’s and DVD’s many of us wouldn’t be able to troubleshoot PC? MAC or Laptop problems now days or simply copy and paste the files from one hard drive to another. You operating system is hosed and you can’t boot , what you are going to do? Hit F8? NO! Boot the Live CD, and troubleshoot with these Five Best Live CD’s voted by LifeHacker’s poll.
* Knopix – Linux operating system with many extra tools to fix your operating system problem.
* Ultimate Boot CD for Windows – Windows based Operating system, great live cd for windows users
* Puppy Linux – Another best friend yet for? Linux Breed.
* Back Track – Has some advanced unix/linux stuff, would recommend for experts.
* Ubuntu – My favorite and very easy to use 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 theirbootable medium.
The term "live" derives from the fact that these CDs each contain a complete, functioning and operational 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 ashard 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.
Some live CDs come with an installation utility launchable from a desktop icon that can optionally install the system on a hard drive or USB flash drive. Most live CDs can access the information on internal and/or external hard drives, diskettes and USB flash drives.
Generally live CDs 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 Puppy Linux which has the ability to save files to the live CD itself or other multisession media, allowing users to carry data, and more importantly, added programs and customized settings, along with them on optical disc.
Most live CDs 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 live CD for other operating systems, such as OpenSolaris, BeleniX and others based on Solaris. Other "live" operating systems include Mac OS, Microsoft Windows, OS/2, ReactOS, NetBSD, FreeBSD, OpenBSD, MINIX 3, Plan 9 from Bell Labs, AmigaOS 4, MorphOS and FreeDOS.
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.[citation needed]. Earlier examples of live OS are of course the operating systems used from floppy, and most widely spread is DOS.
Unlike previous operating systems on optical media, though, Linux and OS/2 "live CDs" were specifically designed to run without installation onto other media like a hard disk drive. The live CD 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.[citation needed]
On a PC, a bootable Compact Disc generally conforms to the El Torito specification. Many Linux based live CDs 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[citation needed].
The resulting environment can be quite rich: typical Knoppix systems include around 1,200 separate software packages. Live CDs have a reputation for supporting advanced auto-configuration and plug-and-play functionality. This came out of necessity to avoid requiring the user to configure the system each time it boots and to make it 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. For this reason, a read-only file system is often merged with a temporary writable file system in the form of a RAM 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. Puppy linux has a savable layer so if you choose to, the next time you boot you can resume (pick right back up again) from where you left off. Each time the CD boots, it looks for the file and then uses it if it has the right name.
In modern live CDs, a read-only file system is merged with ramdisk using transparent techniques such as UnionFS, AuFS or EWF. In MS-DOS and OS/2 systems, ramdrive.sys, can be loaded at boot for this purpose. Boot loaders like syslinux can boot ISO files from USB memory devices.
Live CDs have to be able to detect and use a wide variety of hardware (including network cards, graphic cards etc.) in realtime. This is easily achieved nowadays by udev, hotplug, hal, udisk etc.. which is a common part of all distributions based on Linux kernel 2.6.
Boot code
During live CD initialization, a user typically may resort to using one or more boot codes to change the booting behavior. These vary from distribution to distribution but can most often be accessed upon firstboot screen by one of the function keys.
* Knopix – Linux operating system with many extra tools to fix your operating system problem.
* Ultimate Boot CD for Windows – Windows based Operating system, great live cd for windows users
* Puppy Linux – Another best friend yet for? Linux Breed.
* Back Track – Has some advanced unix/linux stuff, would recommend for experts.
* Ubuntu – My favorite and very easy to use 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 theirbootable medium.
The term "live" derives from the fact that these CDs each contain a complete, functioning and operational 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 ashard 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.
Some live CDs come with an installation utility launchable from a desktop icon that can optionally install the system on a hard drive or USB flash drive. Most live CDs can access the information on internal and/or external hard drives, diskettes and USB flash drives.
Generally live CDs 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 Puppy Linux which has the ability to save files to the live CD itself or other multisession media, allowing users to carry data, and more importantly, added programs and customized settings, along with them on optical disc.
Most live CDs 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 live CD for other operating systems, such as OpenSolaris, BeleniX and others based on Solaris. Other "live" operating systems include Mac OS, Microsoft Windows, OS/2, ReactOS, NetBSD, FreeBSD, OpenBSD, MINIX 3, Plan 9 from Bell Labs, AmigaOS 4, MorphOS and FreeDOS.
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.[citation needed]. Earlier examples of live OS are of course the operating systems used from floppy, and most widely spread is DOS.
Unlike previous operating systems on optical media, though, Linux and OS/2 "live CDs" were specifically designed to run without installation onto other media like a hard disk drive. The live CD 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.[citation needed]
On a PC, a bootable Compact Disc generally conforms to the El Torito specification. Many Linux based live CDs 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[citation needed].
The resulting environment can be quite rich: typical Knoppix systems include around 1,200 separate software packages. Live CDs have a reputation for supporting advanced auto-configuration and plug-and-play functionality. This came out of necessity to avoid requiring the user to configure the system each time it boots and to make it 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. For this reason, a read-only file system is often merged with a temporary writable file system in the form of a RAM 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. Puppy linux has a savable layer so if you choose to, the next time you boot you can resume (pick right back up again) from where you left off. Each time the CD boots, it looks for the file and then uses it if it has the right name.
In modern live CDs, a read-only file system is merged with ramdisk using transparent techniques such as UnionFS, AuFS or EWF. In MS-DOS and OS/2 systems, ramdrive.sys, can be loaded at boot for this purpose. Boot loaders like syslinux can boot ISO files from USB memory devices.
Live CDs have to be able to detect and use a wide variety of hardware (including network cards, graphic cards etc.) in realtime. This is easily achieved nowadays by udev, hotplug, hal, udisk etc.. which is a common part of all distributions based on Linux kernel 2.6.
Boot code
During live CD initialization, a user typically may resort to using one or more boot codes to change the booting behavior. These vary from distribution to distribution but can most often be accessed upon firstboot screen by one of the function keys.
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