Originally Posted by
Ian W
I can't imagine that it was originally set up like that, it is more likely that someone has removed the redundancy from the system in some way possibly through ignorance of how the fault tolerance operated.
Unfortunately I can. In my experience, the original developers didn't design any resilience in. Then an infrastructure architect got hold of it and designed in all of the resilience and fail over architecture in. Then the bill payer saw the price and order it be redesigned to meet a budget 10-50% of the infrastructure architects design. Finally, a solution goes in that doesn't meet the original requirements but meets a price on the basis that the "what-if" scenarios are so rare they can be discounted until they actually happen.......
Been there, seen it, done it and got the t-shirt.
In addition, the one thing you cannot protect against fully in this situation is where the master system writes corruption to the disk. The storage devices then replicate it to the DR location as they believe the master knew what it was doing and you end up with corruption on both sites.