Originally Posted By: tonyc
Wouldn't the task of writing data to these unused hda3 sectors (similar to what tman describes above) be simpler than trying to write to a file on a different partition?

Not really, no -- reliably working out the values of n and x at runtime would be no easier than ioctl(FIBMAP), and that latter has the benefit that you can do it to a file named after your application, and be confident that your data won't get overwritten by the next developer who comes along trying the same idea.

Peter