Robotic library is down

[venkat25_1]

i have 2 drive ,In device manager only 1 drive is showing and another drive is not showing and can you suggest.
when i start a job its show
Robotic library is down on server, Media Server

[Marianne]

@venkat25_1 

I have moved your comment in this 7-year-old post to a new discussion : https://vox.veritas.com/t5/NetBackup/Robotic-library-is-down/m-p/459630

There were lots of suggestions in that discussion - have you read through all of them?

Have you verified that the OS can (still) see the tape library?
Have you checked output of 'scan' command to confirm that the library and tape drives are responding to scsi-commands?
Any device-related errors in Windows Event Viewer?

[Marianne]

@venkat25_1 

It seems that you've been having device issues for 3 weeks now, right? 
https://vox.veritas.com/t5/NetBackup/Re-tape-drive-shows-active-but-the-ready-column-shows-NO/m-p/86...

Your screenshot shows that the OS only sees one tape drive. 
Do you see the library in Device Manager under 'Medium Changer'? 

As an application, NetBackup has no direct access to a device, instead relying on the operating system (OS) to handle any communication with the device.
Any troubleshooting should therefore start at the OS level.

As per the TN that I shared in your other post:

If the Tape Drives do not appear (in Device Manager), the operating system is not able to detect the devices.  Begin by rebooting the server in question and see if the operating system can detect the devices when it comes back up.  In addition, review the Event Viewer Application and System logs to try and determine what event resulted in the drives being lost.  If on reboot, the drives are still not shown in Device monitor, further hardware troubleshooting is required.  Review the cabling, SCSI controllers, HBA cards, or the drives themselves for any problems or errors.  
Consult the hardware vendor and operating system vendor for assistance.