Netbackup Appliance Upgrade from 7X to 8.1 stuck with the error “System_Call_Fastpath+0x16/0x1b”. in my case Appliance upgrade was stuck after doing self-test and Netbackup software and appliance software upgrade. what I observed is that upgrade is completed successfully, however, there is some issue with operating system kernel (kernel panic)

Solution:-

In my case, I had waited for some time but that doesn’t help me, I have rebooted the appliance and able to load the operating system and all the NetBackup services were started successfully . in order to make sure issue resolved, I had rebooted appliance two times and there is no error

It is just one time error, after rebooting issue is resolved.

Since the Netbackup 8.1 is still latest there are only a few articles is available for the same error.