Recovery Strategies

My site has a business requirement: "In the event of server failure, the database must be recovered within two hours to its state at the point of failure", and an assumption "Our disk hardware is so reliable that it is guaranteed to be 100% available" Suspending disbelief of the assumption, I believe that, in all server failures, the combination of the disk and Informix Fast Recovery will always guarantee the requirement without recourse to back-ups/logs (To be precise, all users will be in their last end-transaction state prior to the failure). I further believe that, in circumstances where it's necessary to restore and roll forward logical logs, the requirement can only be satisfied if the log dbspace is available. In the case where the log dbspace had been trashed, or where for some reason the assumption was false, it would only be possible to restore the state at the time that the last logical log back-up took place. Do I have this right? Thanks Neil Truby Chase Manhattan Bank Bournemouth, UK