Testing OS/controller/hardware failure will quickly devolve into extremely specific configuration issues and even fully verifying one particular configuration m

Testing OS/controller/hardware failure will quickly devolve into extremely specific configuration issues and even fully verifying one particular configuration may be meaningless for the next configuration. Fault injection is probably as close as you can get to reliably exercising any fault tolerance properties while still being generic enough to apply to more than 1 real system in the wild.