I have a FreeNAS Server with four network interfaces. The iSCSI traffic goes through two of those interfaces, and each interface has one IP address in a different subnet. As example:
igb0: 192.168.10.1/24 igb1: 192.168.11.1/24
There are three XenServer hosts with only one interface dedicated to iSCSI traffic. So in the schematic are two interfaces on the storage and three as the total on the hosts.
My plan was to achieve up to 2Gbit connection with the hosts, limited as 1Gbit per host.
The problem starts with the different subnetting. I don't know how to put two different IP's addresses on the same network interface on the XenServer hosts. The XenCenter simply don't let me to do this. Another idea was to isolate this kind of traffic with different VLANs. It's OK, but this does not appears to work, either.
EDIT: Unfortunately LACP does not work as expected, there are more info on FreeNAS docs: "LACP and other forms of link aggregation generally do not work well with virtualization solutions. In a virtualized environment, consider the use of iSCSI MPIO through the creation of an iSCSI Portal. This allows an iSCSI initiator to recognize multiple links to a target, utilizing them for increased bandwidth or redundancy. This how-to contains instructions for configuring MPIO on ESXi."
That's why I'm trying to setup MPIO even with VLANs and hacks to achieve the 2Gbit/s for the storage.