I got this error when I went to format a rewritable cd with Disk utility.
Disk was unmounted as demanded.
Error creating file system: helper exited with exit code 1: Error calling fsync(2) on /dev/sr0: Input/output error
What can it be?
You can not format cd-r(w) media. They are not randomly writable like other disks are. You have to use a cd burning program (