v6.2.1 CD boot error: Input/output error

[peter.hentrich]

Successfully:
Verified CD with boot option 'knoppix testcd'
Past mounting /mnt-system
Past mounting /KNOPPIX
Past mounting /UNIONFS
Past symlinks to /UNIONFS

Following error found:
/init: exec: line 742: /sbin/init: input/output error

The following cheat codes were used with no success.
knoppix vga=0
knoppix (1-5)
knoppix acpi=off noapic nolapic pci=bios hpet=off nodma
knoppix acpi=off pnpbios=off noapic noapm

knoppix vga=0 debug -b 3

Using 'debug' boot option and typing 'exit' at each prompt, the system stalls at the following prompt:
BusyBox v1.14.2 (Debian 1:1.14.2-2) built-in shell (ash)
Enter 'help' for a list of built-in commands.
sh: can't access tty; job control turned off
/ #

At this point, I typed 'exit' and then 'init 5' but still have a blank screen.

[kl522]

The input/output error thingie with /sbin/init, seems to be a fairly common problem, not limited to knoppix only. The errors seem to be due to /sbin/init failed to open /dev/console for input/output, but nobody seems to have found out why it happens only to certain systems :-

http://www.linuxquestions.org/questi...-error-397113/

Perhaps you can try to debug it by checking the permission of /dev/console and also do some chmod, when you run it under debug mode.

Cheers.

[peter.hentrich]

Thanks 'kl522' for your suggestion, however, it seems that 'input/output' error could be due to many possible causes. To change the permissions on a clean downloaded distribution doesn't make sense.

In my case the problem was with my CD which explains why a file could not be read i.e. input error.

My solution was simple:

- used a new, clean, high-quality 700MB CDR
- burned at slowest speed 4x
- OPTIONAL: increased the cache and RAM buffer size

As per the forums, most errors are due to:
1. Incomplete/bad download
2. Bad burn

[Harry Kuhman]

As per the forums, most errors are due to:
1. Incomplete/bad download
2. Bad burn

yup, and both easily preventable:
1) Use the torrents rather than the mirrors, and do the simple md5 test. If you don't want to learn how to do either because you have never done them before, then it is very likely that Knoppix and Linux are not for you and you should stay with Windows.
2) Burning at slow speed, as an ISO, with burning software that supports both ISO burning and verification after burning (such as Nero) with verification enabled should give a good burn.

[peter.hentrich]

Harry, thanks for your experienced advice and patience with first-timers like me.

These are simple measures to ensure successful CD/DVDs:

1a) Use the torrents rather than the mirrors

Yes, this is the best option. Using a torrent does not eliminate errors though, as I discovered. Whether by user error or otherwise, my 'uTorrent' download was incomplete even when it said "finished". I had to re-check/re-start my download.

1b) Do the simple md5 test

Yes, this step should be mandatory after a finished download. Foolishly, I ignored this hash key verification and trusted my torrent application to verify the complete download.

For an explanation of the procedure, go to:
http://www.knoppix.net/wiki/Downloading_FAQ#Q:_What_are_these_strange_MD5_file s_that_accompany_the_ISO_CD_images.3F

It's a single command:

md5sum -c KNOPPIX_xxxxxxxx.iso.md5

Here is the erraneous output after my first attempt of the uTorrent download:

md5sum -c KNOPPIX_V6.2.1CD-2010-01-31-EN.iso
md5sum:   
@@@@@@@@@@@@@@@@@@@@@@@@@@ : No such file or directory
  
@@@@@@@@@@@@@@@@@@@@@@@@@@ : FAILED open or read
md5sum: int1e = %08x: No such file or directory
int1e = %08x: FAILED open or read
md5sum: WARNING: 2 of 2 listed files could not be read

Here is the successful output after I 're-checked' and 're-started' my uTorrent download:

md5sum -c KNOPPIX_V6.2.1CD-2010-01-31-EN.iso.md5
KNOPPIX_V6.2.1CD-2010-01-31-EN.iso: OK

Knoppix is working and an important lesson learned.