RE: Fwd: FW: [Bug 47663] New: DVD burned from iso file has incorrect checksum
Hi Andy,
In the meantime I tried to
write an iso-image ( FC3-i386-DVD.iso - fedora core 3 distribution ) to a
DVD+R.
I used the same parameters as created by k3b and added the -dvd-compat
option.
Also here is a problem
concerning the size:
the original dvd has 602151 4k-blocks, while the DVD
after burning has one additional 4k-block.
Did I miss something, or
is there a bug in growisofs ?
Have a nice
weekend,
Winfrid
-----Original Message-----
From: Andy Polyakov [
mailto:appro@fy.chalmers.se]
Sent: Wednesday,
November 03, 2004 5:56 PM
To: Tschiedel, Winfrid
Cc:
cdwrite@other.debian.org
Subject: Re: Fwd: FW: [Bug 47663] New: DVD burned
from iso file has incorrect checksum
> Many thanks for your
explanation, nevertheless, currently there 2
> things which I cannot test
for the moment, is it true, that you are
> saying :
>
> using
DVD-RW would report a correct checksum ( here I know, that at
> least
there is one burning program under WINDOWS, which generates DVDs
> with a
correct checksum )
>
> using DVD-R or DVD+R would be also okay
.
Yes. If unit didn't have to pad the file system image as required by
specification, then a) DVD-RW Sequential, b) DVD-R and c) DVD+R recordings
performed with growisofs -dvd-compat(!) option should pass the 'md5sum /dev/dvd'
test. "Should" means "I won't be surprised if someone runs into a firmware that
will fail this test even for above mentioned recordings."
In any other
combination, namely a) padding to 32KB boundary was required, b) growisofs
executed without -dvd-compat option, c) DVD+RW and d) DVD-RW Restricted
Overwrite recordings, trivial 'md5sum /dev/dvd'
test might *fail*. The
failure however won't be violation of any specification or indicate a bug in
recording software or unit firmware.
As you can see it's a number of
combinations and if you don't want to figure out which particular combination
caused the above mentioned checksum test to fail at any particular occasion,
always verify as much data as you've actually written: 'dd if=/dev/dvd
count=<appropriate
count> | md5sum' and not just 'md5sum /dev/dvd'.
A.
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