New Armory changes are pretty amazing

[zanthor]

Not quite as simple as a couple hard drives. I'm sure they're using enterprise level SAN storage arrays for all of their database storage, adding a couple disk drives doesn't work the same as adding them to a server, and costs a shit-ton more.

It's basically a high-traffic web database server. SAN, maybe not...but controllers and backup get to be the expensive part for a large database compared to the drives themselves. And no, they're not getting the $100 Newegg special...but even at 3x for some enterprise drives and +$$ for the controllers, backup, cooling, etc...it's not that costly compared to the overall cash flow.

Add to that, they were probably storing the data anyway for research into the effects of various changes and trends over time, and the cost of this is extremely cheap at several times the cost if it helps drum up increased player interest or satisfaction. The primary problem of an MMO is retention - if they can improve that, across as many users as WoW has? It makes them a LOT of money later. Armory has its usual privacy qualms...but this is a pretty solid move.

I'd all but guarantee they are using a san due to the fact that the DB gets so much traffic they need to be able to spread reads and writes across spindles. Direct Attached Storage just doesnt keep up with even the low end SANs you can get. Combine that with their need to be always online and highly available and I think you would be challenged to build a raid that could perform as well on DAS as you can on SAN.