I began trying to backup my dvd collection to an external hard drive. I do this my making disk images(.iso) from the dvds. To do this I use disk utility > new image > save as dvd/cd master. Started with some Battlestar Galactica. First 6 disks of season 1 went fine. Next 3 disks of season 2 went fine. First disk of season 2.5 I get an input/output error about 75% through the process. Any ideas?
Disc might be spoilt or faulty most probably. Clean the disc, enable any error-correction on your image conversion software, and give it a go again.
This could be a problem with the drive, or (more likely) a problem with the DVD. Perhaps there's a scratch on it, or maybe just a smudge. It's tough to say.
If you copy the files directly, you can still play it with VLC.