On the, "Get close to the application" thread, remember that any I/O request satisfied from MDC is likely to be satisfied (on modern boxes) in less than a microsecond. Even cached, anything that involves a conversation with a channel is going to experience a service time that is several orders of magnitude higher.
It's always important to reflect on the cost and consider the best way of investing ones limited currency (in this case, central / expanded storage), but some MDC payback is usually a no-brainer. I believe this to be especially true when dealing with synchronous I/O - and how much I/O nowadays is truly, "application asynchronous"? Not as much as in the, "batch sequential" days, that's for sure. (Not, of course , that CMS has ever been strong in the, "I/O overlap" department from a single user's perspective.) It would be an unusual configuration that would benefit from the reassignment of all MDC storage to, "other uses".
