Found an old Redo Backup image of my ThinkPad on my external hard drive. Decided I wanted the space back, but didn't want to just delete it. (Pack rats point to me when they want to talk about people who hoard things.)
Didn't want to risk 'bit rot' on the DVD's I burned it too, so I ran Parchive to get Reed-Solomon error-correction files, then burned the Redo files and the *.par files to a set of disks.
But that's not being paranoid enough.
So, I ran DVDisaster on the ISOs that I'd built, then ran Parchive on the resulting ECC files, and made an ISO image from them. Then I re-ran DVDisaster on that ISO to include as much ECC data as would fit, and burned two copies.
So, if any of the primary DVD's bit-rot, the DVDisaster data should get them back. If not, I'll restore what I can, then use the PArchive files to get the Redo data back.
I have to admit, I didn't check to see if the Redo files and their Par files are spread out well enough that I can loose an entire DVD without being unable to recover.
Maybe I ought to burn another set...
(That direct link isn't responding right now, so here's the Wikipedia entry for Redo Backup)