Lots of great articles on the intertubez about disk alignment and RAID configurations but I haven't found an answer (or a good way to test, and yes I know about SQLIO) for a simple scenario:
Suppose I have 4 local physical disks available to me and I'm going to create an OLTP DB (for the sake of arguing let's say we're 50\50 on reads and writes, or otherwise average usage). Here are two scenarios that I would consider:
1) Two RAID 1 drives. Create the DB with two data files, i.e. one data file on each drive
2) One RAID 10 drive. Create the DB with one single data file
In the RAID 1 scenario (as I understand it) SQL will round robin writes between the two data files, thus creating a software equivalent of striping. RAID 10, on the other hand, handles the striping at a hardware level. Those differences aside, I haven't found a good technical explanation - or numbers to back it - for what's happening under the covers that would make me believe one option is better than the other.
So which of these two scenarios is more ideal and why?
Kendal Van Dyke