Identical ISO creating with mkisofs on subsequent run

Gerard Beekmans gerard at
Tue Sep 14 09:17:59 PDT 2004

Hi guys,

Maybe one of you guys can provide a hint or two how to go about solving
a problem I need taken care of.

I have uploaded a 3 GB DVD ISO that I now have to make some changes to.
I need to make these changes locally so I can test to make sure it's
bootable. Uploading the image to the remote site will take an estimated
10 hours which I would like to prevent if possible.

What I'd like to do is create the ISO locally and test it. If it's good,
then I make the same changes on the remote server and create the ISO
there too. Then I need to somehow make sure it is created properly.

Initially I thought to compare the md5sums of the general ISO images,
but they differ every time mkisofs is run. One of the changes are due to
a time/date stamp inserted. Maybe other things as well.

I can't find from the manual page how to not have that date created
stamp written or allow me to set it to a specific time rather than the
current clock's time.

Maybe there is a different way I can go about it.

Just to make sure: it's not a matter of making sure the right file (and
sizes) are in the same directory. I can simply run ls -lR on it and
compare the two lists easily. It's once the binary ISO is created I want
to verify it's the same as locally without having to upload the entire 3
GB file. That would really be a pain.

An alternative might be to create a binary patch? I have the old ISO I
uploaded. I can then create a new ISO and after testing create a patch
of it, then upload the patch file, binary patch it remotely and run
md5sum to make sure it's the same.

Is that feasible? How do I go about that?

Gerard Beekmans

/* If Linux doesn't have the solution, you have the wrong problem */

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