[X4U] How big is a DVD really?

[Michael Winter]

On Nov 22, 2006, at 9:15 PM, Stroller wrote:

> So how large is the overhead of the file-system when I drag & drop  
> a file onto a DVD-R on my Mac?

Sounds simple but, depending on what you're doing, there may be no  
way to know ahead of time. For disks that can also be read by a PC  
(the default for most programs), Finder information will be included  
in hidden files. So suddenly its not just the size of the files, its  
the number and type of files, since info will be stored for each one.

To complicate matters, the "overhead" also includes catalog  
information which is format dependent and also increases with the  
number of files.

Bottom line, I don't know how you can precisely calculate it all  
ahead of time. I know its not an elegant solution, and not the one  
you want, but I'd just go with 4.0 GB of data for each disk -knowing  
you will be wasting space on each disk. Increase the size if they  
consistently show a significant amount of space left.

Sorry I don't have a better answer.

-Mike