Modifying the FreeBSD6.2 ISO Image

Martin McCormick martin at
Wed Nov 7 09:02:57 PST 2007

	I think I have boiled this problem down to one point of
failure. I need to modify a file in the 6.2-RELEASE-i386-disc1.iso
CD. The image is 601229312 bytes in size.

	Following instructions from a list member, I did the

mdconfig -a -f /usr/local/src/6.2-RELEASE-i386-disc1.iso
mount -t cd9660 /dev/md0  /mnt

	This all worked perfectly as one now sees the entire
file system under /mnt.

	At this point, one should be able to reverse the process
by using mkisofs at the top of the tree which should produce
another iso image. It does but the image is 1072242688 bytes
large. this is pretty close to twice the correct size. Also, tar
produces an identically-bloated file.

	Any ideas on how to put tar and mkisofs on a diet?

	In order to make the modification, I must tar  cf
somefile.tar . I bet when things are right, that tar file will
be about the size of the image.

	Originally, I had posted several messages about tar
complaining about an out-of-order file. I think this is probably
related to whatever mechanism is used to fit the FreeBSD image
on the disk. This last time, I created the memory disk and
mounted it with no error so the problem appears to be something
I am not setting in both tar and mkisofs. I am thoroughly stuck.

Martin McCormick WB5AGZ  Stillwater, OK 
Systems Engineer
OSU Information Technology Department Network Operations Group

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