I didn't say you didn't learn anything. But you seem to be making excuses for why you shouldn't know some very basic things about MongoDB. It uses a memory-mapped file. How can that be larger than 2GB in 32-bit system?
It has async writes...this is pretty well documented by 10gen and is also something noted by a lot of tutorials, blog articles etc. You should have known something this basic about a database so important to your business.
None of that would bother me in the slightest if you were not still here defending such basic mistakes and blaming them on 10gen.
Come on, database (or any other system) that just silently fails to add new data?
2GB limit is clearly mentioned in the logs, that's fine, but anyone that sees this would expect that DB would start "screaming" loudly wherever it can (logs, response to the user on EVERY communication with the server, during any select,insert and others) that it reached this limit.