[Debburn-devel] mkisofs/genisoimage and md5sum

[Thomas Schmitt]

Hi,

> has anyone done any work to combine the steps such that
> we/I only have to stress my hdd one time? :-)

In my backup tool scdbackup there is a pipeline for this purpose:
  formatter | checksummer | writer

"formatter" can be afio, mkisofs, genisoimage, or xorriso.
The "checksummer" is a program out of scdbackup. But it
should be quite easy to create such a filter out of
program md5sum.
"writer" can be cdrecord, wodim, growisofs, cdrskin, xorriso.
(Note: wodim and cdrecord cannot do piping of afio
with DVD or BD. With ISO images, use option -isosize.)

The result of "checksummer" is appended to a log file
on disk.
Additionally the checksum is appended to the image on
media. (Note: wodim and cdrecord cannot do that on DVD/BD
even with -isosize and thus would need to get padded
to a generous tsize= value.)
My backup tool is able to read the media, compute its
MD5 and simultaneously to scan for the recorded checksum
at the end of the image. As soon as this is found, both
sums are compared and reading ends.


Have a nice day :)

Thomas