Online backups require a server that is configured for deferred agent startup. To configure such a server, you must set the defer-agent-startup property to a valid time-out value (in minutes) in the server property file. In the following example, the time-out (shown in bold) is set for 240 minutes, or four hours:

[server]
     control-agents=agent-name    
     database=source-db-name     
     transition=manual
     transition-timeout=1200
     defer-agent-startup=240

For more information, see Server properties.