2015-03-24T17:28:39.760-0400 I STORAGE [initandlisten] exception in initAndListen: 72 Metadata contains unexpected value storage engine option for directoryPerDBExpected true but got falseinstead, terminating

if you are migrating to directoryperdb, or incorrectly specified it and shouldn't have, you will get this message as i believe directoryperdb=false is in storage.bson. This is not a very clear message and i also did a web search on the error message so it isn't documented either.

We should make it clearer, and also document it, and perhaps mention storage.bson somewhere in the message, maybe.

Also whitespace is missing.