BE 9.1 backup rate slowing down

[maya14]

I'm using BE 9.1 with Sony SDX 900V tape drive. Backup starts with speeds of just over 200 MB/min but then drop after few minutes to 6 MB/min. The rate will never increase and normally i cancel the backup after few hours almost days. It takes about 1 hour to backup 1 GB. Backup is not local but over LAN.
I have upgrade the firmware of tape drive,re-install BE drivers and used the Sony Tape Tool for diagnostics but stil no improvement. Backups used to work fine and at an acceptable rate - min 200 MB/min.
What can cause this sudden slowdown of the backup rate?

 

[maya14]

I have tested BE to external drive but with same results, thus eliminating backup hardware.
So it seems it can only be network or software related.

 

[maya14]

I have 2 servers to backup over the LAN. Backup to one server is fine but backup to our main file server not. End up running at 6MB/min and then "dies" later on and i have to cancel backup.
Check network connection to server but dont see anything wrong.

Please help...

 

[maya14]

Where are all the BE experts????

Tried Windows backup and was running fine. So what is causing BE to do this. Have re-installed BE a few times now and everytime with the same result.
Cant be network issue because Windows backup was running fine.

 

[bigchiefdan]

Im no expert, but I would look at several things just to rule them out.
I would verify the port settings on the swtich are correctly matched to the NIC (speed/duplex)
I would check to see what the processes are running at as far as network load to this server.
Since its the main file server, I would be curious as to what the backup would run at after hours. If its during the day, it could be dragging due to several people accessing the files its trying to backup.

Good Luck.

 

[maya14]

Some feedback:

Installed 12.5 but had same problem. Decided for some reason to uninstall Symantec Endpoint Network Threat Protection on servers and that seems to do the trick.

Backup rate 800 MB/Min now

Can anyone explain this...