iSCSI hardware initiator for VI 3 implementation

[TonyJK]

From VMWare documentation (IO Compatibility Guide for ESX 3.5), it seems that we have only limited choice for iSCSI hardware initiator - Qlogic QLA4050c / QLA4052c / QLA4060c and QLA4062c.

We would like to seek your advice on the following issues

1) Would it be better to use 2 iSCSI hardware initiator (like QLogic QLA4050c) than 1 QLA4052c for redundancy ?

2) If we use 6 NIC, does it mean that 4 NIC for VMs / VC and 2 QLA4050c for connecting to the switch which will be connected to the iSCSI Storage ?

3) If iSCSI hardware initiator is used, does it mean that we have to disable software initiator in ESX Hosts (At least not enable it) ?

Thanks

[Dave_Mishchenko]

Your post has been moved to the Enterprise Strategy and Planning forum.

[EllettIT · Accepted solution]

Here's my thoughts:

1 - I would think redundancy would be preferrable if you have the money for it

2 - If you use 6 NIC's it would be 6 NIC's for VM's / VC / Service Console and 2 HBA's for iSCSI if I understand you correctly.

3 - with ESX 3.0.2 the software initiator was disabled by default, not sure if this is the case with 3.5. I want to say it is or at least you have to configure it to work. I would assume you wouldn't want to disable iSCSI in general as you'll need that for the HBA'sa

[kjb007]

I'd agree with redundancy. Since you can only have 2 hardware initiator ports, beter to go with 2 single port cards as opposed to a dual-port card.

6 NICs is not limited to the type in ESX. You can have 6 NICs and your HBA's, and use your HBAs for storage, and then 2 for vm's, and 2 for service console, and 2 for vmotion

Your software initiators are separate entities, so you can have both hw and sw, as far as I know.

-KjB

[TonyJK]

It should be 4NIC and 2 QLogic iSCSI HBA.

Are 4 sufficient for VMs / VMotion and VC connection ?

Thanks

[mcowger]

They are. We run that as well.

--Matt

[PhilipArnason]

I suggest a hardware initiator for only the most demanding applications. I would do some load testing using the software initiator, because the added administration of a hardware initiator is frequently not worth it.

Philip

[KungFuJoe]

1) You would want to have 2 separate physical HBAs (not a single card with dual ports) for true redundancy.

2) Are you saying you have 6 NICs + the HBAs or are you counting two of the NICs as HBAs?

3) You don't have to do anything to the software initiator in ESX if you go hardware.

As an added thought, going hardware vs software initiators is becoming harder and harder to justify these days. There is no difference in throughput...the only difference is the hw initiator alleviates some CPU load off the ESX host. You also need HW if you want to boot off the SAN.

[Cotay]

Honestly, we run Qlogic 4052s in each host and they've made our setup overly complex. Also, I'm not convinced that they add any performance. Qlogic support is email only and has been completely unresponsive. There are difficulties patching firmware on ESX hosts. The list goes on.

Stick with S/W iSCSI. Like most of us, you will run out of RAM before CPU and overhead shouldnt be an issue.

[TonyJK]

Many thanks for your advice.

As there is not much performance gain, there is no point to spend both time & money on HW iSCSI inistiator.

Thanks again