You're right, it's not official documentation, but it was the first thing I read when I decided to start learning Mongo. I've also seen 10gen hand out hard copi

You're right, it's not official documentation, but it was the first thing I read when I decided to start learning Mongo. I've also seen 10gen hand out hard copies at meetups in NYC. Anecdotal, I know, but maybe helpful to someone. There's also a reference to the issue in your second link, though it's not super clear. http://docs.mongodb.org/manual/faq/replica-sets/#are-write-operations-durable-without-getlasterror http://docs.mongodb.org/manual/faq/replica-sets/#are-write-o...