I am using PE and was inserting custom object records through API, there were around 3 millions of record. I thought storage limit will exceed but instead it is using 382% of storage. Can any one let me know the reason behind this? Also do I need take care of anything because of this?
Salesforce will not just have your org blocked because you are exceeding storage limits, but will charge you an additional cost if this is a permanent situation.
You should contact your account executive for more information.
EDIT: A similar question was posted here.