The device is probably /dev/dvd or /dev/sr0.

You can tell what DVD size you need by looking at the file size for that 
Ubuntu dist, but you can probably install from a USB drive. Saves you a 
DVD.

On Tue, 10 Dec 2013, Tom Poe wrote:

> Hello:  Have an old desktop with ubuntu 12.04 currently.  Want to figure out 
> what my dvd device is, and how big a dvd I need to burn ubuntu 12.10 to 
> replace 12.04.  Any advice appreciated.
> Tom
>
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