On Sun, 02 Oct 2005 20:03:08 +0200, Chris F Clark <cfc@shell01.TheWorld.com> wrote:

> I'm trying to upgrade a rh 9 system to centos 4.1.
>
> I burned the part 1 iso image onto a cd using cdrecord.
>
> Given my experience upgrading rh installations, I next tried booting
> from the cd. It fails with the message(s):
>
> ISOLINUX 2.11 2004-08-16 Copyright(C) 1994-2004 H. Peter Anvin
> isolinux: Disk error 80, AX=42CC, drive 9F
>
> Boot failed: press any key to retry.
>
> I have tried booting the cd on a couple of systems and it does the
> same. Moreover, I know that bootable cd's work on the system (laptop)
> in question, as that's how I put rh 9 on the system in the first
> place.
>
> However, I've looked at the cd (under windows) and there are
> directories on the cd, not just an iso file. So, I don't think I
> wrote the cd wrong.
>
> Am I correct in assuming that perhaps there was a write error on the
> cd and the boot image was corrupted?

Did you bur the CD yourself? Do you have the iso image on disk somewhere?

From the linux you already have,

n=$(( (the size of iso in bytes)/2048 - 50 ))

dd if=/dev/cdrom bs=2048 count=$n | cmp isoimage -

If you get "EOF on stdin" the CD is likely OK.
Notice that it does not work to compare the last part of the
iso this way because of a bug in the linux kernel. This bug
does not affect the operation of the cd as a mounted file system.

If you want to burn cd's that are possible to verify with dd,
you need to pad the iso image on the cd when you burn it.

My guess is that the CD is corrupted.

-Enrique