Knoppix 3.3 can't boot. corrupt image?

[lindseyp]

Hi. I couln't find an answer to this by searching, I'm trying a first-time attempt at burning a bootable CD.

I downloaded KNOPPIX_V3.3-2003-11-03-EN.iso and burnt using Nero 6.3.0.2, I can't boot from the resulting CD, the light flashes as if it's trying to read it, then reverts to booting off the hard disk. In windows XP I can't read the CD, I get the message "Disk not formatted" - "Windows cannot read from this disk ,it may be corrupt, or in a format not used by windows"

I though I may have a bad burn, so I tried mounting the .iso with Virtual DAEMON manager 3.44. Trying to browse the image that way gives the same error.

Is this a bad image? Should I try d/l again? Should I be able to browse the CD with WinXP after burning?

[Cuddles]

LindseyP,

I am going to take, a newbie one that is, stab at this...

Can you download, or did you download, the checksums for the ISO? I think they are something like MI[something], or something like that. I think you can test your downloaded ISO to verify the ISO file is correct, or corrupt, with those. [?]

I had someone else download the 3.3 ISO for me, and burn a cd with Nero as well, unfortunately I only have a 56k line, and they had a dsl, so I asked them to do it for me, so I didn't do it myself, and am going from memory here, on this subject.

But, I did recall someone, one of the "guru's" here, on a subject about burning your own distro cd, and I recall them saying to download both the ISO and the checksums, using the checksums to verify the ISO download, burning the cd, and using the checksums again, to verify that the burnt cd is ok too.

Any Guru's want to ring in? Am I correct on my posting here? Or, did I do as I often do, bugger it?????

Hope I helped here,
Cuddles

[EmDee]

On windows you'll need md5sum to compare checksums. A simple google search for "md5sum.exe" gave me www.etree.org/md5com.html; just download from there and copy it to your c:\windows\system32\ directory.
Once you downloaded the iso-image file and the corrosponding md5sum file from your favorite knoppix mirror, put both files in the same directory such as *\Desktop (don't rename or modify the *.iso or*.md5 files!!!) and launch the windows command line. Then cd into the directory where you've put the knoppix image and the md5sum file. Now type this: "md5sum -c whatever_knoppix_version.md5" The "-c" option makes md5sum automatically compare the checksum of the iso-image and the checksum written in the md5sum-file. Now wait a minute (this takes about 3 minutes on an amd 1400) and see what md5sum has to say; it should either say "ok, checksums match" or "nope, checksums don't match" or something like that. If the latter is the case, you can toss the image into the garbage and download again
Yeah, I know life's tough But good luck anyway!!!

[Cuddles]

O M G ! ! !

I got ONE right!

Yippie for me... [giggle]

Cuddles
[ps] yeah, I know, I get one right, and lots more wrong, but, heck, I take what I can get [LOL]

[EmDee]

Oh, if you don't understand my babbling http://theopencd.sunsite.dk/md5.php gives a pretty good explaination too.
BTW, you have to make make sure that nero or whatever burning program you use actually writes the iso-file as an image! Simply burning the huge image file on a cd won't cut it; click on "file" and then you should see something like "burn iso-mage". When done, windows should be able too "see" a couple files and directories on the cd. Anyway, when I was using windows I always used http://www.burnatonce.com. It's free, it's small, it works!
Well, verifying the cd is a little more tricky; http://www.troubleshooters.com/linux/coasterless.htm gives a good explaination for this.

[Cuddles]

EmDee,

I've seen documentation on the process, using "most" of the popular burning software, one mentioned by name was "Nero", and since I had the program, I read it pretty well.

I think it was either in one of the forums here, one that specifically talks about burning new distro's, or it was in the DOCS above the list of forums, somewhere here, thats for sure...

It mentione about "ensure that you select 'write from image file', and any other options to ensure the disc is created as bootable" - that was from the Nero aspect. Nero can "duplicate" cdroms, and as they did in early floppy days, you create a image file of the disc, and use the image file repeatedly, to make other discs. Knoppix/Linux has used this same process, to cut down, the duplication process. They distribute the "image file", and you just go through the last part. This way the file system, and structure, are left intact, as it was on the creating system.

Cuddles
[ps] All this is useless trivia, after the fact.

[eyeball2]

I get the same type of errors as the original post here; when I burned my 3.3-11-19-2003.iso I forgot to check the status of the "burn all at once" and the "burn a session" flag in Nero. It's best to "burn disk-at-once" always, and especially on a Knoppix disk. Stupid me cancelled the burn, and then used the same disk on the next try. (Shoulda tossed it and got a new one.)
The effect was to burn two boot sectors, which can confuse the drive as it tries to read. Windows won't touch it, and acts like it's a blank disk. Linux boot floppies will report "filesystem not found" and revert to a floppy shell.
However, the cd will boot properly on fairly modern drives, since they are set up to read both the primary and the secondary (backup) boot sector on a disk. Older or odder drives must be coaxed to read the backup boot sector: trick the drive into reading both by shutting the drive door AFTER it's begun to handshake to read the first boot sector, and before it finishes. This forces it to keep reading until it finds one, and often the "corrupt" disk can boot. Tedious, yes, to slam the drive door 10 time as you reboot, but better sometimes than begging for bandwidth from some DSL hog. Another trick is to make a cycle of booting from floppy to from cd, and/or rewriting the MBR (use a win98 boot disk, then fdisk /mbr IF you're using FAT32 and Win98 as a second OS, for example --only) to force the hardware to look for MBRs next the time you boot. Sometimes that helps to get the disk to boot the first time you slam the door.
Anyway, don't give up on that disk just yet--Knoppix is just too good to waste even one!

[lindseyp]

Thanks for your help, guys.

The answer to my question, really, was that the .ISO image, if intact, should mount properly. The fact that it didn't means there's something wrong with it.

I had been doing everything else correctly.

I downloaded a new image, did the checksum check, and everything was fine.

My new CD now boots properly.

Thanks again.