This question is low-priority. Steve, Richard
or others, please reply when you have some time.
I notice that the new woody r3 CD images have
long null voids---hundreds of kilobytes---at
their ends. This is fine, but strangely a small
problem respecting the images seems emerge on my
installation. Cdrecord (4:1.10-7, distributed
with woody r2) does not appear to want to record
all the trailing nulls. I burn the image onto
the CD, then dd(1) the image from /dev/cdrom
back to the hard disk, and some of the trailing
nulls are missing.
The problem seems to be with cdrecord(1) not
with your images, but I never saw the problem
with earlier images; I see it only now with
woody r3.
For example, debian-30r3-i386-binary-1_NONUS.iso
has 326262 2048-byte blocks, of which the last
150 blocks are null. If I
dd bs=2048 count=326262 if=/dev/cdrom \
of=debian-30r3-i386-binary-1_NONUS.iso
then only 326244 blocks are recovered. These
include 132 of the 150 trailing null blocks, but
the last eighteen are missing. Just to be sure,
I manually add eighteen null blocks, and the
md5sum does then come out exactly right.
Cdrecord was invoked with the -data and -pad
(default pad size == 15 blocks) options. If
relevant, the machine runs a 2.4.24 kernel.
The question is not tremendously important and I
would not advise you to spend a lot of time on
it; but if you have seen an effect like this one
in the past, where trailing null blocks are not
recorded, I would be interested to learn of your
conclusions or observations in the matter.
--
Thaddeus H. Black
508 Nellie's Cave Road
Blacksburg, Virginia 24060, USA
+1 540 961 0920, t@b-tk.org
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