P4500 G2: Separating iSCSI data from SAN management

[jcooper]

I have a two-node P4500 G2 SAN. I've added the dual-port 10 Gb NIC in each unit, so each now has 2 x 1 Gb and 2 x 10 Gb NICs. Servers that will be mounting LUNs on the SAN are HP blades in c7000 enclosures, using HP Virtual Connect Flex-10 10Gb Ethernet modules.

I would like to separate the SAN management traffic from iSCSI storage data. My thought is the 10 Gb NICs on the P4500 G2 nodes will connect to a switch used only for iSCSI traffic, on a different subnet from the 1 Gb NICs. I would put the CMC and a FOM on the management subnet.

Is this doable? How should the network be configured on the P4500 to make this work? If there is a better configuration, I'm open to suggestions.

Thanks is advance for your comments.

[Emilo]

Yes you can do this.  You have to remember though that the management traffic needs to see the iSCSI traffic.

I dont really think you gain much from this approach. It's not like the management traffic is going to saturate the wire.

You would set up both your VLANS make sure they can see each other. In the CMC under the network section you select the iSCSI network ( its a drop down that shows all the bonds and nics) you pick one and that will be your iSCSI lan. You will know if you have it setup correctly if your nodes start to go offline. 

[oikjn]

people always ask about this.  the design of the HP system is all "in-band".  There is no point in splitting out the management traffic.  As long as you have your gateways setup correctly you don't need to have your administration computers directly connected to the SAN network.   Any OOB management would be at the hardware level and done w/ the L/IO connection which you can put into whatever network handles your IPMI traffic, but the design of this HP SAN assumes you have a routed SAN w/ a gateway to your other nextworks.... if you don't you are probably missing out on at least 1/2 of the reasons for using this system.

[jcooper]

I see. My concern was not that the management traffic would cause any contention issues with the iSCSI traffic, rather that I want to keep the iSCSI traffic isolated from other unrelated server and workstation traffic. That was the thought behind a physically separate iSCSI network.

But from what you're saying, perhaps I'd be better off keeping everything on the iSCSI subnet, and routing my CMC traffic there? Or I suppose I could even run the CMC on a machine that lives on the iSCSI subnet?

Your quick replies are appreciated!

[oikjn]

what other "workstation/server" traffic are you thinking about?  while the iSCSI network should be routable to your other networks, you definitely want to segregate your iSCSI traffic to either its own physical network or a VLAN.  As long as you have a gateway for your SAN, you don't need to keep your CMC instance "inside" the SAN and that way you can keep the "SAN" limited to nodes and initiators only.   For me, use vLANs to keep my SAN traffic isolated and have one port on my firewall connected to the SAN to act as a gateway and allow for routing to our remote site and allow me to manage the SAN from our production LAN.

 The CMC is only used for short-term monitoring and configuration changes, there is no problem routing that from your production network to your SAN.  I'm a little unclear if you were thinking about keeping your SAN and LAN on the same logical network and only split by subnet, to that I would highly suggest you either get physical split switches or use vLANs to keep your SAN split from your LAN.

[jcooper]

oikjn, your comments are helpful. In fact I have a separate switch dedicated to the SAN, with the intent of keeping the iSCSI traffic physically isolated from the production LAN. (I know, I should have two for redundancy -- maybe in next year's budget.) I created separate vNets (virtual networks using the Virtual Connect Flex-10 modules) for iSCSI, which appear as separate physical NICs to the servers. Where I went astray was putting the 1 Gb NICs (bonded) in the storage nodes onto the production LAN so that the CMC could see them. That's causing a variety of problems.

I'll do as you suggest and configure routing on the SAN switches out to the production LAN so the CMC can connect (and the nodes can get NTP etc.). Is there anything else you can think of that I should look at?

[oikjn]

thats about it.  a 2nd switch is always nice for redundancy, but I wouldn't lose too much sleep over it w/ your small setup simply because switch failures are so rare.

I would make sure that you have flow control enabled for everything connected to the SAN as well as jumbo-frames (only if everything can have that enabled, if not leave it off for everything).

beyond that, the storevirtual system should be pretty strait-forward.  The manuals help a lot for setup and best practices so the first thing you shoudl do when in doubt is read them or the CMC help and it generally does a good job of answering most questions.

[Prakash Singh_1]

Hi,

For P4000 SAN solutions querries you can also visit the HP Guided troubleshooting tree.

Below is the link for HPGT:

http://h20180.www2.hp.com/apps/Nav?h_pagetype=s-905&h_lang=en&h_cc=us&h_product=304617&h_audience=smb&h_client=s-h-e010-1&h_audiencerestrict=true&lang=en&cc=us

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