Just to note, the MongoDB journal is basically a write ahead log and has been around since 1.8. It's not simple, you are correct, and involved remapping portio

Just to note, the MongoDB journal is basically a write ahead log and has been around since 1.8. It's not simple, you are correct, and involved remapping portions of memory privately, and leads to some inflated numbers on the virtual memory reporting side. There's a great write up here: http://blog.mongodb.org/post/33700094220/how-mongodbs-journaling-works http://blog.mongodb.org/post/33700094220/how-mongodbs-journa...