topic Re: HP P2000 G3 iSCSI SAN Implementation Questions in MSA Storage

HP P2000 G3 iSCSI SAN Implementation Questions

Craig A. Russell — Fri, 26 Oct 2012 14:49:52 GMT

I am in the process of implementing a new HP P2000 G3 iSCSI SAN and have a few questions as this is my first SAN implementation (our currently SAN which I didn't implement isn't setup very well either so will be using this info to set it up better for other purposes).

SAN Configuration

- P2000 G3 iSCSI w/dual controllers, 16x 10k 300g SAS drives

Switches

- HP Procurve 3500yl 48 port. Currently just one but will have another one in 1-2 months. They will be setup with all connections split between the two of them for proper redundancy.

- Seperate isolated VLAN for iSCSI traffic

Servers connecting to SAN

- Multiple ML/DL servers that will have dual port nics. They will be split between the two switches when complete.

- C3000 Blade enclosure will have a single interconnect dedicated to iSCSI traffic to the SAN.

- P-Class Blade enclosure with RJ45 patch panels will have dedicated 1-to-1 connections to the switches.

SAN LUNs

- DFS share (200g LUN)

- LoB scanned documents (100g LUN)

- Exchange 2010/2013 stores (50-100g LUN)

- Clustered Shared Volume (CSV) for a HA Hyper-V implementation (1tb LUN)

- Microsoft System Center Data Protection Manager phsical server full backups (1tb LUN)

Setup

The SAN will be connected to the Procurve 3500 switch(es). The ML/DL servers will have dual port nics connected. The C3000 enclosure will have a dedicated interconnect connected to the 3500. The P-Class enclosure will have the RJ45 patch panel connected with 1-to-1 connections. So this will be a typical setup.

Questions:

1. Flow Control: Does the P2000 support Flow Control? I can't seem to find documentation for it that suggests it does or how to enable it. This is listed as a best practice for SAN implementations.

2. LACP: I planned on implementing LACP between the C3000 interconnect and the Procurve 3500 switches. Is this recommended? I keep reading that you should not use LACP (or NIC Teaming) with iSCSI. I planned on having two ports aggregated to each 3500 switch.

3. Jumbo Frames: I do not plan on implementing this. Everything I read says a 1g iSCSI network won't benefit from it.

4. MPIO or MCS: Which is the best to implement in our scenario and what policy is best to apply? Round Robin? Least Que Depth? Other? I can't seem to find any information on MCS with the P2000 SAN only MPIO.

Thanks for your help!

Re: HP P2000 G3 iSCSI SAN Implementation Questions

Joshua Small_2 — Wed, 07 Nov 2012 04:22:31 GMT

Hi,

Some answers:

You should not use LACP between your servers and switches because this precludes those servers from using intelligent multipathing.

It's fine to use however, on various uplinks not directly connected to your servers.

I also can't find anything definite about "flow control support", but it's an iSCSI best practice in general and I've always implemented it on switches - I would assume therefore that the P2000 supports it.

The thing about Jumbo Frames is that, even when you may find the reality of it is a small increase in performance, the moment you log a ticket about performance someone will say "oh we recommend jumbo frames" and it will be difficult to retro-fit. It's not hard to set this up at implementation time.

Re: HP P2000 G3 iSCSI SAN Implementation Questions

GGoede — Mon, 25 Feb 2013 14:07:16 GMT

I have been fighting a very long time with this issue.

Somehow, nobody knows or wants to give a straight answer to this.

The P2000 does not support Transmit Loadbalancing to a single host, so between any one host to the P2000, it will always use just one NIC, effectively limiting you to 1Gbps.

Playing with the patchswitching at every IOs, but this will just barely give you any performance gain.

The only answer I have for you at this point is to do one of the following:

1. Change the controllers for 10G Ethernet controllers and upgrade your whole storage back-end to 10G (expensive)

2. Change the controllers for FC and change your whole storage back-end (for this SAN) (also expensive, but less than 10G)

3. Upgrade/replace the P2000 for a P4000 (you've guessed it, also expensive)

I'm sorry I can't be of much help here.

I've been beating my head on this matter too.

If in the meantime, you got any workable solution, please let me know.

Regards,

George