Data replication

Hello, I would like to make my database robust. Currently I am running disk mirroring on Informix5.0. I have in mind using HP Switchover to replicate my servers, but I have no idea as to what is the effect on the database. Do I then still need disk mirroring or would Switchover take care of it. I understand that Informix7.1 has some data recovery features and I wonder is there anything useful that I should take note of. The main question is that if I were to buy replication software on system level like the Switchover on HP-UX, do I still need to activate the replication function provided by the Informix database. Or is there a better way to integrate both of them so as to make my database and system as robust as possible. Would appreciate any advice and I thank you for your time.