I'm designing the server structure for my application in case things go well. I have one server DB connected to multiple server who process connections. All those with lots of RAM and fast processors. (still looking for a way to use the multithread because now it's dumb apache php... so loooots of ram needed).

Upon an answer from those servers, the client can then connect to another server to retrieve pictures using the address he previously got from the db.

Is it a good idea to have one database server with let's say nginx and ssd disk having to send all pictures to everybody? or should I have multiple server accessing to a shared ssd disk drive or multiple disk updating each other? Also should I put a lot of RAM on the database server? because probably there wont be a picture more popular than another.