The amount of space required in the exporter warehouse depends on
Which objects are to be exported
How long the records are to stay in the export warehouse
How busy the Identity Manager servers are
WorkflowActivity and ResourceAccount are usually the highest-volume exported models. For example, a single workflow could contain multiple activities, and as each workflow is executed, Identity Manager could create dozens of new records to be written to the warehouse. Editing a User object may result in one ResourceAccount record per account linked to the User. TaskInstance, WorkItem and LogRecord are also high-volume models. A single Identity Manager server can produce over 50,000 object changes to be exported in one hour of operation.