Backup To CDR Burner

This essay is about a suggested student project in Java programming. This essay gives a rough overview of how it might work. It does not describe an actual complete program. I have no source, object, specifications, file layouts or anything else useful to implementing this project. Everything I have to say to help you with this project is written below. I am not prepared to help you implement it; I have too many other projects of my own.

I do contract work for a living, which could include writing a program such as this. However, I don’t do people’s homework for them. That just robs them of an education.

You have my full permission to implement this project any way you please.

The Roxio (née Adaptec) Easy CD Creator is not suitable for routine backup because it makes you respecify the list of files to backup every time. If you use their layout save, it won’t capture new file in the directories you back up, and it complains about any deleted files.

What you want is a back that works by taking either:

A list of directories, directory wildcard, files and negative wildcards, and feeds to produce the list of files that need backing up.
You leave special marker files lying around your disk that give hints to the backup software what needs to be backed up when. The files could have zero length. E.g.
never.!!! means never backup this directory or its children.
daily.!!! means backup this directory and its children daily.
monthly.!!! means backup this directory and its children monthly.
trip.!!! means backup this directory and its children just prior to taking a trip.
A directory might have multiple marker files in it. If you want to get fancy you can put additional information inside the marker files.
Just prior to the backup, your utility scans the disk looking for marker files and composes a list of files to be backed up. You could use automated tools to manage these files. You can get a list of unmarked directories, so you don’t forget something crucial.

Now how do you take this list of files and get it them on CD?

Use the file at a time method where you use a driver to tread the CD much like a hard disk. The result is not as fully compatible as the second method.
You create a phony Roxio CD Layout file and fool it into thinking it is one of its own. Unfortunately this is a binary file and the format is undocumented. However, you may be able to figure enough of it out for the current purposes. The bulk of it is just a list of filenames preceded by a length byte.
Create a giant 600 MB *.cif or *.iso file which is a CDR image, including data. Then feed that to Roxio CD Creator.

If you wanted to write your backup at a lower level, there are several things to consider:

Backing up and restoring the platform dependent file attributes, e.g. owner, read-only, create-date, last-accessed-date…
Making sure you have exclusive access to the files during backup so nobody changes them while you are in the process of backing them up. You want to guarantee an consistent set of files on restore.
Spanning. If every thing won’t fit on one CD, DVD, floppy, tape etc, how do you split files over the boundary and put them back together on restore.
Creating an index to the backup, so that you don’t have to scan the entire backup from beginning to end just to restore one file.

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