If the Cisco Unity Structured Query Language (SQL) database increases in size and space on the hard-drive is too limited, move the SQL database to another drive with more space.
Perform this procedure to move the Cisco Unity SQL database with the Enterprise Manager:
Note: Restarting Cisco Unity service also works.
For related information, refer to these documents:
Shrink the Cisco Unity Database Configuration Example
Unity 3.x, Unity 4.x