block, I suspect. My DVD trauma was IDE-induced. Jens is mulling theIf it's in the block layer, perhaps using a device mapper error target can help in testing. One could write a table to map an entire partition to a logical volume, then replace it with a table that maps a few sectors to the error target.
problem - I'd suggest you coordinate with him.
It would be a good thing to fix.
It's moderately hard to test, though. Easy enough for DVDs and CDs, but
it's harder to take a marker pen to a hard drive.