We moved part of our data from mysql to mongodb, not so much for scalability but more because it is a better fit for files and non-tabular data.
In production we currently store:
- 25 thousand files (60GB)
- 130 million other "documents" (350GB)
with a daily turnover of around 10GB.
The database is deployed in a "paired" configuration on two nodes (6x450GB sas raid10) with apache/wsgi/python clients using the mongodb python api (pymongo). The disk setup is probably overkill but thats what we use for mysql.
Apart from some issues with pymongo threadpools and the blocking nature of the mongodb server it has been a good experience.
