LiveCD Boot Error (invalid module)

[Mook]

Greetings folks -

I was excited to give Knoppix LiveCD a try, but so far I'm having trouble simply booting up. I downloaded the latest CD version via BitTorrent, burnt the image, but when I try to boot the machine with the disk I get the following:

Accessing KNOPPIX CD at /dev/hdc...insmod: error inserting '/cdrom/KNOPPIX/modules/cloop.ko': -1 Invalid module format
insmod: error inserting '/cdrom/KNOPPIX/modules/cloop.ko': -1 Invalid module format
Can't find KNOPPIX filesystem, sorry.
Dropping you to a (very limited) shell.
Press reset button to quit.

(and then a few commands)

Can anyone shed some light on how I can rectify this?

Thanks!

[Harry Kuhman]

An unusual error. Obviously you know how to burn the iso as an image. good. Did you burn it at low speed? Even though you used BitTorrent, I would double check the md5 also, in light of this strange error. And if those two things are not the issue, I would consider another burn at slow speed on a 700 meg CDRW and see if that behaves any differently. And if the system has more than one optical drive, absolutely try the other one, as it sounds very much like a problem reading the disc to me.

[Mook]

Thanks for the quick reply Harry - the original burn was at 'max' speed, I'll try a reburn at 1x. I'm also downloading the DVD torrent as well, in case the reburn doesn't work.

I'll report back tomorrow on how things go. 8)

[Harry Kuhman]

the original burn was at 'max' speed, I'll try a reburn at 1x.....
I don't know that 1x is needed, or even that most new burners and software are willing to do 1x. But, as outlined in the downloading faq, burn speed is an issue. I do all of my CD burns at 4x. I do have a DVD burner that insists on not going lower than 8x when burning a CD with Nero 6 software (it must be a Nero issue since I have burned CDs slower on it with other software), but I generally just use a different CD burner and get Nero to do 4x on that.

For DVD's I've had mixed results. I have some very crappy media (Generic from CompUSA) and I'm hard pressed to get anything to burn and verify over 50% of the time on that. But I've found with better (still inexpensive) media I can burn DVDs better at 4x than at 2.4x speeds. 4x works well though and I never push my DVD burner faster even though it claims it will go 12x.

For a long time I resisted accepting that burn speed is an issue. After all, if well respected drive makers like Plextor make drives that will burn CDs at 48x, 52x or 56x, then it should be fine to burn at that speed, right? But I've seen problems with high speed burns over and over again. Often, when making a data CD, the massive amount of error correction data in a CD can hide burn errors from you (a 700 meg CD actually holds over 800 meg of data including error correction information). But quite frankly, even with a data CD I want that error corection to kick in later, to save me from data rot, or optics that get a little dirty, or evn a scratched disc; I don't want to use it up because I had to do a burn in less than 2 minutes rather than 15 to 20, and then find that I don't have the data later when I need it. The problem seems to be much worse when booting (I can only speculate that maybe some of the error correction does not kick in during the booting process) and high speed discs have been seen to take longer to boot (http://www.knoppix.net/forum/viewtopic.php?p=78583#78583) if they boot at all.

[Mook]

I ended up just downloading the full DVD version instead, checked md5, and burned at 4x.

Works perfectly now, and looks great - can't wait to play around with it. 8)

Thanks for everything.

[Harry Kuhman]

....Works perfectly now....
Glad to hear it. I expect that if the CD ISO's MD5 sum is good and you burn it at 4x it will boot also. It can be handy to have a CD available for recovery work, not all systems have a DVD drive yet.