I am having trouble getting a dual-booted iMac running Ubuntu 15.10 to read data from an external USB CD/DVD drive. I have confirmed that the drive works on another machine, and I have tested it with multiple non-commercial DVDs, so I doubt the problem is a faulty drive or media.

When I try to copy data from a DVD to the hard drive, it copies for a second or two, then when the DVD drive starts to spin, I receive an error that states "Error splicing file: Input/output error" and the disk is temporarily unmounted.

Using both Disks and the Terminal, I have confirmed that the drive is mounted in /mnt/ and has a block file at /dev/sr0. That means it is mounting OK, right? I'm not sure what to look for next.

Hi & Welcome to Linux Questions.

I've never encountered the issue your having, sorry your having trouble.

Try running the lsusb command. Does lsusb see the external CD/DVD player?

Run dmseg and see if there are any clues in the log as to what might be going on with the external player. Maybe these links will help.

https://answers.launchpad.net/ubuntu...uestion/172778
http://www.linuxquestions.org/questi...py-4175423816/

If all else fails you could follow the instruction for Manually Mounting.
https://help.ubuntu.com/community/Mount/USB

http://www.linuxquestions.org/questi...sb-dvd-936084/

HTH