Booting from Live CD Problem

[Simpson]

When booting my PC from a 3.4 Live CD it goes through the hardware OK then come up with a message "Unable to handle kernel NULL pointer dereference at virtual address 00000074" the boot sequence then hangs. Any advice welcome. The same CD boots fine on my laptop.

Fogive the "newbie" question - learning all the time!

Simpson

[wcloteaux]

There could be any of several problems. As I am usually swamped with these problems I can only speak from my experience. Three things have caused me headaches with this symptoms. First, RAM that is not functioning correctly. If you have two RAM strips swap them and watch for a change in symptom. If so remove one and try again. If necessary, remove the one and install the one you removed originally.Try again. No luck, wipe the hard drive and reinstall. I do recommend that , if you have it, install Knoppix 3.3 , then if it works you can install another version. I do not feel that the cd is bad as I have never had this happen. Power supplies are occasionally a problem but it can be detected by listening to the fans . If the fan speed varies up and down , then it might be wise to change the power supply. If ther is version of Linux on the hard drive over which you are trying install, occasionally, for reasons I don't know it corrupts the LIVE DISK install. Try a reinstall, do not change anything by using cheat codes. Once you have diagnosed the problem, reinstall in any manner you like. Hope this is some value.

William

[Simpson]

Thanks William - the PC is fine (only 3 months old) in all respects when booting into Windows XP. I have tested the RAM and all is OK. I suspect I need to use 1 or more "cheats" for Knoppix but don't know which or how to as the PC is autobooting from the CD.

Simpson

[chris-harry]

i have had problems with my live cd before... now i am a newbie... so really dont take my word to head..

my live cd wasnt working in the computer i wanted it loaded onto... why... well it was really simple... the cd worked on everyother computer... why not mine... well... i will tell you... there was nothing wrong with my cd... it was just that my CD-Rom was a very very fussy... yes fussy. sometimes it would wanna read others not... i cant use it when it heats up... thats my 2 cents... have fun. seriously... dont try and chuck the computer across the room... not really worth it.

[wcloteaux]

When you boot from the live cd, you will reach a screen that says boot:. At this point enter your desired cheat codes. Personally, I don't use cheat codes unless absolutely necessary. If you need the cheat codes they are available , as I remember on this site. If not go to Knoppix on google you will find them. Each version Knoppix has a cheat code list. I haven't noticed any difference.I wiil make one more suggestion, before you use cheat insure that there is no other problem. Install without cheat codes and if everything is OK then reboot and enter your cheat codes. Agaain , take your time go slow and think about what you waant to do.Cheat codes can be of value only when know what each is supposed to accomplish, and can be the source of problems. I do encourage you to go forward and be ready to reinstall if need be . Make this fun thing, I do and I make lots of mistakes. Good Luck,

William

[wcloteaux]

Chris-harry ,yes I have the same problem with the fuzzy cd. Iusually make a back-up immediately when I get my new cd. Part of the fuzzy is scratching the under side of the cd. If that is the problem you can remove some of the abrasions with tooth paste rubbed from CENTER to the OUTSIDE do not rub coaxially as it will guarentee to destroy it.Weel this is all for this post.
William

[Simpson]

Thanks for the info guys. I'm sure the problem isn't with the CD or the CD reader (I have both a CD reader and a CD reader/writer and the same problem occurs with both). When booting from the CD, the Knoppix loading program starts automatically, no "Boot" prompt. It's only when it is almost at the end of the Knoppix loading sequence that the problem occurs.

Simpson

[shah]

No boot prompt,no knoppix lilo screen?Boot directly?
Then there is something wrong with your cd.

[Simpson]

My brain hurts! Of course I have a boot prompt - I was just hitting the "Return" key in my desire to get Knoppix to load quickly! Now by pressing F2 I have discovered the "failsafe" cheat. If I add that to the boot prompt all runs well. Just like to find out what was causing the problem though ..................

Thanks for your help.

Simpson

[shah]

Since you just hit enter, I assume you only try booting using kernel 2.4.26.
Try booting using kernel 2.6, cheatcodes: knoppix26

If it doesn't work, try using different combination of cheatcodes. You could try with: knoppix26 noapic noagp nodma pci=bios