Re: Checking the integrity of the Debian DVD
Hi Andrew,
Eventually I settled for the command
#cmp /dev/cdrom /home/.../debian-6.0.0-DVD-1.iso
When the byte-by-byte comparison process hits the end-of-file in the
iso file, it terminates with a
cmp: EOF detected in the iso file.
Otherwise it terminates with an error.
That is a pretty thorough integrity check of the DVD, provided the
integrity of the downloaded iso file has already been checked using
SHA256SUM.
I have upgraded from lenny to squeeze and presently exploring it.
Thank you very much for your suggestion anyway.
Kind regards,
--
Mr. Goldin R. Bennet
Department of Instrumentation and Control Engineering
National Institute of Technology
Tiruchirapalli - 620015
INDIA
Quoting Andrew McGlashan <andrew.mcglashan@affinityvision.com.au>:
Hi,
Goldin R. Bennet wrote:
I have downloaded the Debian-6.0.0. (Squeeze) DVD iso files and
they passed the SHA256SUM integrity test. But after writing them
on the DVD using K3b, Brasero, or GnomeBaker, when I checked the
integrity of the DVD using SHA256SUM they failed. It appears, when
the disk is closed, the additional characters inserted by the DVD
writing program changed the SHA256SUM of the disk. Is there any
solution for this problem so that the integrity of the disk also
can be checked?
I think if you know exactly how many bytes or blocks to read and you
read just that many, then you should get the right answer.
dd if=/dev/dvdrom bs=2048 count=xxxxx|sha256sum -
For example:
# ls -l debian-live-6.0.0-amd64-gnome-desktop.iso
-rw-r----- 1 root root 1172307968 2011-02-06 17:36
debian-live-6.0.0-amd64-gnome-desktop.iso
# echo $((1172307968/2048))
572416
# echo $((572136*2048))
1171734528
dd if=/dev/dvdrom bs=2048 count=572416 |sha256sum -
Cheers
--
Kind Regards
AndrewM
Andrew McGlashan
Broadband Solutions now including VoIP
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