quick (and perhaps foolish) question: MD4sum of CD

Leonard den Ottolander leonardjo at hetnet.nl
Fri Sep 26 16:36:01 UTC 2003

Hello Robert,

> > > "md5sum /dev/cdrom"

> i'm pretty sure i have had perfectly good CDs produce a bad MD5 sum
> when running the above command.
> is it possible that there would be extraneous junk at the tail end
> of the CD that would throw off the checksum?

 Maybe the error output also gets used in the checksum generation. As said, 
I use dd | md5sum for this. In that case I get correct checksums even if I 
do not specify a bs and count and see I/O errors. Probably because the 
error output does not get piped to md5sum.

 Ok, I did a test of md5sum /dev/cdrom[1] on both my cd-player and cd-
writer. I get a correct result with the writer, and no result due to an I/O 
error with the player (ie it chokes at the end of the disk, dd with no 
count works fine).


How clean is a war when you shoot around nukelar waste?
Stop the use of depleted uranium ammo!
End all weapons of mass destruction.

More information about the test mailing list