We have a large virtual environment and our Backup Exec server is a physical server. Symantec server is connected to our tape library via 8Gb fiber connection. Network is a flat 1Gb LAN.
We know the slow performance is not caused by the library or drives (LTO5) because the backup exec server can backup at 8 GB / min. I assume that is because it's going straight to the library via the fiber connection.
The next fastest server runs at 1.5GB / min to tape. That is acceptable performance but still seems kinda slow. The worst performers are backing up at 60MB / min, which is about as bad as it could get. That is slower than USB2.
I thought maybe it was a network transfer issue but all servers can copy data to the Backup Exec server much faster than the backup is going.
All servers are on the same network, same blade enclosure, same SAN storage. There is nothing different about any of them other than their backup speeds.
I've read all of the performance tuning documents but in our situation it's not all servers that are affected, only about 1/2 so we know that the environment is in good shape.
What else can we look at?