Transcript 350Presentation

Live CDs
What is a Live CD?
Prerak Parikh
What is a Live CD?
CD or DVD containing bootable CD-ROM disk
that loads and boots an OS
Instead of using the hard drive to boot, the
computer uses the Live CD
What is a Live CD?
Can be made from many different Operating
Systems
Gives the ability to run a complete, modern
Operating System
Some Examples
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Windows
Ubuntu
Debian
Mac
Solaris
Origins
Jason Morrison
The Beginning
The original concept
 Why CD's?
 What changed?

Live CD's Develop
CD drives / burners expand
 Faster drives allow practicality
 The cause of the boom

First Releases
Yggdrasil Linux (1992~1993)
 DemoLinus (1998)
 Change in development direction

How It Works
Dan McFadden
How It Works
- Insert CD into CD-ROM Drive
- Automatically boots
- Enter BIOS, change Boot Sequence
How It Works
Since there is no reading from or writing to a
hard drive, a RAM disk is created that simulates
a hard drive.

How It Works
Normal Setup
Boot Strap / BIOS
Hard Drive
OS
OS in RAM
I /O
Hard Drive
Live CD
OS
Boot Strap / BIOS
I/O
Live CD
OS in RAM
RAM Disk
RAM Disk
- Orders of magnitude faster than interacting with
a hard drive
- Limits amount of memory, however
RAM Disk
Digression: You can set up your own RAM Disk
outside of Live CD's
- Through kernel
- Through user space applications
Uses
Jon Sherman
The Obvious
Test drive
 Use without installing
 Use as a normal computer

Security
Allows use of an untrustworthy computer
 Prevents second owner from viewing windows
event logs

Hardware Upgrades
Installing new memory
 Testing new software version

Troubleshooting
Decide if problem is caused by hardware or
software
 System restore
 Data recovery

Performance Upgrades
Run file system completely in RAM
• Improves performance
• Improves power efficiency

Disadvantages
Sam Perlow
Software Disadvantages
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Installed programs forgotten each time
Can't be updated
Must be configured with each run
Need prior programming experience to
customize
Hardware Disadvantages
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Limited H/W compatibility
Some older computer can't boot from CD
Slow to boot
Advantages
Nidhi Shah
No need to install anything on your
computer
As its name implies, the live CD runs live from
the removable medium.
You don’t need to install Linux to your hard disk.
Just insert the medium into your computer and
reboot to bypass your hard disk and run the CD.
You can test your computer
Helps you check that your hardware is supported
before committing to a Linux system.
For example, you will know in advance if your
printer, video card, network card, or other
component will just work with your selected Linux
system, or whether you might need to do some
extra tweaking.
Doesn’t disrupt your installed computer
system
You can run the live system without
touching the contents of your hard disk.
The entire operating system is on the CD or
DVD, and uses your computer’s RAM to
hold temporary data.
Other Advantages
A user with some programming experience can remaster the distribution as he sees fit.
After making the changes, the resulting disk image is
written to CD ,which is reliable and convenient Live-CD
as before, now filled with your choice of software.
It is enough to recall such distributions as Linux LiveCD
Router -- a Linux distribution designed to share a
broadband connection over WiFi, Trustix.
Sources
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http://www.freesoftwaremagazine.com/articles/live_cds
http://www.livedistro.org/
http://en.wikipedia.org/wiki/Live_CD
http://www.livecdlist.com/