We have a PowerVault TL4000 with 2 drives. Our backup software is Backup Exec 2014 and we have an IBM SAN N6210. We upgraded the SAN this summer to OnTap 8.2.1 and since then we have issues when backuping data from the SAN. At first, backups from SAN and servers ran fine but wouldn't run at the same time, we found it was a problem with Backup Exec 2010 R3 so we upgraded to 2014.
Since then, both types of backup can run at the same time, but data backups from the SAN often "freeze". The backup are done by NDMP, everything is connected by fiber. What seems to occur is the backup starts, loads a tape and starts backuping. If the data can fit on the tape, it finishes without problem.
But when the tape is filled, the backup "hangs" there a bit and after a couple of minutes, the byte count resets to 0, the tape in the drive isn't changed and it changes to the "Queud" state and runs indefinitely. Every other task that starts are also getting queued, even though the other drive is empty and the job won't cancel. We have to reboot the library and the server running backup exec in order to be able to backup again. And the worst, in some RARE occasions, the backup can complete correctly.
Since OnTap 8.2.x, it only supports NDMP v4, we tried to verify which versions are supported by the library to be sure but couldn't find info on that. We checked all tasks and all configs are okay. Any idea?