VM 2008 Server with iSCSI storage

[Aggy]

Hi

So I have 4 hosts, each with 12 network cards, 4 lan, 4san, 2 dmz and 2 vmotion.  All are running esxi 4.1.

I have a windows 2008 box with 1 vnic on the lan and 4 vnics connected to the san virtual machine port group.

I've installed and configured the equallogic multipathing hit kit on the vm and can see it has multiple connections going to 2 luns i've created on the equallogic SAN.

However when copying a large file, 50gb, it only utilizes one of the network cards, there is no multipathing happening to the san.

Does this have something to do with the Virtual machine port group at all?

At the moment the port group has 4 VMKernel Ports, one for each physical nic, each with it's own ip.

Thanks

[idle-jam]

have a look at this: http://www.yellow-bricks.com/2009/03/18/iscsi-multipathing-with-esxcliexploring-the-next-version-of-...

[weinstein5]

Potentially - how is the Load Balancing configured on the virtual switch? There are 3 load balancing methods available within ESX/ESXi - Port based, MAC aaddress based and IP Hash -

Port based - based on the virtual port the vNIC is connected to a physical NIC will be chosen for out bound traffic

MAC based - based on the MAC address of the vNIC is connected to a physical NIC will be chosen for out bound traffic

So you can see with these two methods only a single physical NIC will be used

IP Hash - a physical NIC is selected based on the originating IP address and the destination IP address - as long as you have traffic going to multiple IP addresses the traffic will go out multiple physical NICs - but the traffic to a single IP address will still only go out a single NIC-

Hope this helps

[Aggy]

Yup that's how our vmware farm is set up, and equallogic multipathing is installed and working well for VMWare storage, however what i'm after is presenting a raw lun straight to the windows 2008 server to facilitate using VSS for backing up purposes. So the virtual machine has 4 virtual network cards which it uses with MS iSCSI initiator to connect directly to the SAN, not through VMware and installing a hard drive.

However with tests it shows that when copying a large file, each san network card is utilised at 25%, disable two and the remainder are utilised at 50% which means it's only using one of the physical nics of the host, when i would prefer it to use all four!

[Aggy]

At the moment it's set to Port, i'm tempted to change it to IP Hash as the traffic is going to multiple ips on the iSCSI SAN....

[weinstein5]

Definitely but you will need to make sure the physical switch is configured for LACP or Etehrchannel in cisco speak - 

[Aggy]

So i have to join all the ports from the esxi host to a LAG group? (using dell powerconnect switches) as opposed to just being normal ports?

[weinstein5]

That is correct - remember switches are layer 2 devices and get confused when they see the same MAC address (the Layer 2 address) are registered on different switches - 

[Aggy]

Sorry i'm probably being stupid here, but why is it the same mac address if every physical nic is different...?

[weinstein5]

It is because the physical MAC address is not used - a virtual MAC address is generated for a virtual NIC ports - management and virtual machine - so going back to my description of IP hash the iSCSI packet being generated coulf out any of the physical NICs but it would be the exact same virtual MAC address -