This isn't a perl solution, but it's how I like to do backups:

(Assuming you want to backup the /data directory)

tar cvzf - /data/ | split -d -b 4000m - /backup/backup.tgz
[download]

This creates files with names like backup.tgz01, backup.tgz02, backup.tgz03, etc. Each file is about 4G, which fits on a DVD-W.

To unpack the archives, just do this:

cat backup.tgz* | tar xvzf -
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