topic Re: iSCSI NIC teaming in StoreVirtual Storage

iSCSI NIC teaming

bublik — Tue, 15 Nov 2011 16:41:47 GMT

Hello All,

I am seeing 85% iscsi interface utilization on my iscsi network adapter that is on physical windows 2003 host.

There is no NIC teaming for iSCSI even though I have 2 of them configured.

I have P4500 G2 28.8 SAN. Networking configured with ALB.

Can anyone tell me if HP recommends to do NIC teaming on my windows host? I know some manufacturers recommend not to.

Will jumbo frame configuration help me to resolve bottleneck on my GB network?

Can't do 10GB. not affordable at this time.

Re: iSCSI NIC teaming

Dan Nichols — Tue, 15 Nov 2011 17:58:59 GMT

Have you installed the HP DSM for MPIO?

This will install Windows MPIO and enable multipath support and load balancing for iSCSI.

Re: iSCSI NIC teaming

bublik — Tue, 15 Nov 2011 18:13:10 GMT

I did but by looking at interface utilization sometimes only one iSCSI interface is used heavily. So it does not load balance correctly I suspect.

Re: iSCSI NIC teaming

Dan Nichols — Tue, 15 Nov 2011 18:22:25 GMT

Have you created a connection to the iSCSI target (the cluster IP) from each iSCSI NIC source IP address?

Re: iSCSI NIC teaming

bublik — Tue, 15 Nov 2011 18:27:30 GMT

Yes, I did. Specified different source IP and specified the target for each iSCSI adapter. I have MPIO policy set as round robin. By looking into task manager i see the both interfaces are being used so maybe it is working correctly. I have to look into my utilization reporting to see if it was incorrect.

But if I chose to minimize the utilization with the fact that there is no budget for it, do you know if configuring jumbo frames would help to minimize network utilization?

Thank you

Re: iSCSI NIC teaming

Dan Nichols — Tue, 15 Nov 2011 18:33:42 GMT

I have had little success with jumbo frames in the 1Gbps world. The advice I have been given is that implementing jumbo frames on a 1Gbps network will make little to no performance improvement. I presume that you have enabled flow control though? This should stop your network from grinding to a halt when heavily loaded.

With 10Gbps jumbo frames is recommended for optimal throughput.

Re: iSCSI NIC teaming

bublik — Tue, 15 Nov 2011 18:42:06 GMT

Flow control is not enabled. Not sure how evenly DSM MPIO is designed to balance the traffic but I don;t think it is working right. It is a small traffic when I took this snapshot. So if there would be larger traffic the difference would be substantial i think.