About the tape drive or robot offline
If you have a problem with ACSLS drives going offline, try to configure the drives in an UP state or reset the drive. If drives persistently go offline, duplication may hang.
Also, if the tape drives are listed as AVR control in the Administration Console Media and Device Management node, there may be a problem with the robotics control. List all drives as robotically controlled (that is, TLD, ACS, and so on). They are converted to AVR control if a problem occurs with the robot. To diagnose the problem, examine the system logs (for example, /var/adm/messages on UNIX systems) for error messages. You can also use the robotic test utilities (such as robtest) to further debug the problem.