I'm working on an MMO. All of the player and environment data lives on a server and is kept in memory. There's a "world" object which keeps track of all of the maps, characters, etc. and their relations to each other.

To avoid data loss in case of a crash, I've been periodically serializing the world to disk. The trouble is, this object can be quite large, so when the server starts writing, there's noticeable in-game slowdown for a few seconds, which I'd like to avoid.

Any pointers on how to go about this in a more efficient way?