If you try to perform a long-running operation, such as creating a portal site or a document library (Web Storage System-based), while another long-running operation is running, you will be taken to the Configuration Database Locked page. The operation that is currently running excludes all other long-running operations from the configuration database so that the task you are attempting to perform cannot run at this time.
Releasing the lock on the database might result in the failure of the currently running operation. Releasing the lock is not recommended unless it appears that the current operation has failed.
You must be a member of the SharePoint administrators group to complete this procedure.