I know the topic might be confusing but the problem itself seems bizarre to me. if i'll take ubuntu's iso file (on this occasion i'm using 12.0.4-2 server) and apply it to a usb drive with the following command:
dd if=/path/to/iso of=/dev/sdc bs=1m
every server i try can boot from the usb drive without a problem and everything is fine and dandy.
HOWEVER, if i re-master the iso using the following steps:
mount -o loop /path/to/iso /mnt/iso rsync -av /mnt/iso /some/directory mkisofs -D -r -V "LABEL" -cache-inodes -J -l -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -o /path/to/new/iso /some/directory
dd if=/path/to/new/iso of=/dev/sdc bs=1m
the usb drive is not bootable. this happens even if i dont change anything in the content of the iso. just copying it and rebuilding the iso removes the bootable option.
my goal is to create the iso file to be 'dd' ready. so we can just deploy it on any usb key without any other software what am i doing wrong?