How Did Someone Send Me a CD-R with 3.5GB Written to It?
How Did Someone Send Me a CD-R with 3.5GB Written to It?
You mean a physical CD-R (maybe mislabelled for some reason?)? What does isosize -x /dev/ show? If you cat it to a file is it 3.5GB? Try different drive if possible? Dunno whether sparse files have something to do with it, check with hex editor.Also see archwiki for optical disk drive for more tools to research.
I have searched for compression methods to no avail. I suspect the CD drive used has compression built into the driver. I cannot find very little information online about this.