Backup exec 2010R2 and iSCSI speed issue

[mrbios]

Hi there,

Currently running backup exec 2010R2 on our file server

3 drives on the file server are iSCSI volumes, each iSCSI volume comes off a separate port on the NAS, each one is configured to use a different subnet, in this case:
172.18.69.2
172.18.67.2
172.18.73.2

The file server has two network connections, one to the same subnet as all the servers, and another connection the iSCSI comes in on with an IP of 172.18.67.3

When running a backup through backup exec the backup of exchange, vmware hosts etc is all nice and quick (2000-2500mb/min) but as soon as it hits the backup of 2 of these 3 (only 2 are backed up) volumes it hits a sudden decline down to 500mb/min which is woefully slow!!

Now that I've looked over the settings, i know it's not setup efficiently and i could switch it around to be much better.......naturally i work all this out the day the kids come back so I can't actually do any of it right now!! >_< but even with that in mind it shouldn't be going 500mb/min, does anyone have any ideas as to what could be causing this?

 

[TangoSixteen]

Jumbo frames enabled?

How many NICS have you got and what load balancing is going on with VMWare?

For redundancy and speed I would team as many NICS as possible, with perhaps two or three PER LUN (if you can)

What is the SAN that is providing the storage?

 

[mrbios]

the SAN is an Eonstor A16E-G2130-4 with the latest firmware installed, which i think has actually added support for port teaming in one of the recent releases.

File server has 3 network ports:
2 port Intel pro/1000PT card
1 onboard HP NIC (unsure of the exact model but the server is an ML350 G5)

No port teaming is setup on the server, previously had the two 1000PT ports teamed but we replaced an old 4108GL core switch with an 8206 recently and had a few issues with it, haven't got around to sorting that

Previously when we had backup exec 12.5 and our old configuration of the eonstor everything to the file server went through a single port, rather than 3 volumes over 3 ports, so i wondered if i'd screwed anything up along the way