Say my data store is going to increase in size, if the data increases how storage manager would manage the data. Does storage manager split the data with different domain machines ( definitely that is not the case)?
How exactly would the process work? What is the recommendation in this area, key-value store?
If you have a storage manager that is soon to run out of disk space, you can startup a new storage manager with a larger disk subsystem or that points to extensible cloud storage such as Amazon S3. Once the new storage manager is up-to-date the old one can be taken offline. This entire operation can be done while the database is running. Generally, we also recommend that you always run with at least 2 storage managers for redundancy.
If you have more questions, feel free to direct them to the NuoDB forum:
http://www.nuodb.com/community