In re-mastering, the first step establishes /mnt/hdb3 as rw ....it is ext3 Linux with 30GB of free space.

Second step is to ....cp -Rp /KNOPPIX/ /mnt/hdb3/

When this step is executed while booted in KNOPPIXv3.8 from a DVD +RW disc , multiple errors are reported as the copy is executed.

These are input-output errors.

What defect in my reads could cause the problem? My cdrom is a SONY crx320e. I also have a SONYDRU540 which produces the same result when booting from that device.

As I understand the re-master procedure this step places the KNOPPIX/KNOPPIX file into the rw file /KNOPPIX in /mnt/hdb3 (ext3). The format for /KNOPPIX/KNOPPIX file in the iso is compressed. On the CD/DVD the file is called /KNOPPIX/KNOPPIX.sh.

No mention in the re-master procedure as to what format exists in this copy step; compressed or non-compressed. A statement of fact in this regard would aid in understanding how to utilize re-mastering technique. Since the reported size of the file being copied (copy is from the CD/DVD KNOPPIX source) is around 1.7GB, one could assume it is uncompressed and assumptions aren't good ideas. To establish the /KNOPPIX file being copied as an uncompressed file requires that the KNOPPIX LiveCD/DVD de-compress it. If this is true, it is paramount for the user to know since this step is hidden from the user and may create a defective file transfer(the subject of this post).
If it is indeed an uncompressed format of the /KNOPPIX/KNOPPIX source, it would help in understanding what is happening while re-mastering.

It is probable that the re-master procedure performs well for most users.

In this case it seems to fail the opening round.