After writing an ISO image using Brasero, I discovered that the md5sum of the target DVD is different than the ISO image, despite no readability errors.
What has caused that difference?
When you do this kind of verification , md5sum or sha1sum you must be sure that your reading the same amount of data .
stat --printf '%s\n' file.iso blockdev --getsize64 /dev/sr1
if the data does have the size , you must compute on the smallest size . to do this :
dd if=file.iso bs=2k count=9000 | md5sum dd if=/dev/sr1 bs=2k count=9000 | md5sum