I have been building iso one after another, each incorporating some changes. Along the way I am able to mount the resuling iso images under virtualbox for simulated effect. Yet somehow I notice there is a screwup at a point where I could not build new iso anymore. It has problem mounting cdrom. it turns out that cdrom is mapped to hda all the time even though I have discovered that somehow I accidentally change the primary master device to secondary master hence the cdrom should have been mapped to hdc instead of to hda. So the building of iso fails because it could not access the device. I have been wondering how this happens since udev is supposed to take care of these devices creation.. Then something dawns on me perhaps that in writing this ISO perhaps the whole dev tree is copied into the rootfs so whatever udev has done in booting the rootfs will wipe it all out! I am wondering if this is the actual scenario. If so, should there be a way to exclude the dev tree from incorporating into the new iso?