ISOs in Ubuntu
To make an ISO from CD/DVD
Place the media in your drive but do not mount it. If it automounts, unmount it.
dd if=/dev/dvd of=dvd.iso # for dvd
dd if=/dev/cdrom of=cd.iso # for cdrom
dd if=/dev/scd0 of=cd.iso # if cdrom is scsi
To make an ISO from files on Hard Drive
Create a directory with the files you want.
mkisofs -r -J -o /tmp/cd.iso /tmp/directory/
To mount an ISO
mount -oloop /path/to/cd.iso /mnt/image