Just a question, was this 'crash test' a power-off test? For example, turning off the computer while Derby is running?
If so, you should probably read this article:
TL;DR, anyone who expects complete durability (non-corruption even during power loss) should disable the write-cache on their hard-disk. There is no doubt this will cut the write performance quite a bit. Applications needing both complete durability and high-performance should consider a controller with a battery-backed write-cache.