Advice? I got lots of advice. My application may perform different than your application so metrics are irrelavent.

I wouldn't waste a mirrored pair by dedicating it to the OS and the Oracle Software. Ideally, I would setup three pairs (d0, d1, d2) and mirror across two controllers(c0,c1).

With only three devices, I wouldn't worry about seperating my data and indexes unless there was serious I/O contention for one of the indexes. I would spread my data AND indexes out on all three devices in LMTs with system managed extents. I would do the same with my undo. I would have two members per log group writing to d0 and d1 and use d2 as my log_archive_dest. Depending on how much TEMP is used, I might make three temp tablespaces and assign a third of my users to each.