If you open the dell case you'll see a small white dongle which enables the TCP Offloading and iSCSI Feature to the onboard nics. These nics acts as a "dependent" iSCSI HBA from the VMware view. Youre right that these HBAs doesnt support jumbo frames and IPv6.
Well... in most cases jumbo frames doesnt bring a better performance. Monitoring normal workloads for our EQLs (1GbE and 10GbE) together with some low level Open-E iSCSI solutions there isnt a big difference.
So dont worry about not using jumbo frames!
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Thanks for the reply. I think I can let go "Jumbo Frame" from my mind. But I am still undecided between using software iSCSI and HBA. I know either one will work fine but I still want to make the best choice to our environment.
Is it correct to say as long as HBA is an available option, we should always choose it over software based?
It depends on workload I think whether or not you benefit from jumbos. As for always taking hardware, I wouldn't really argue with it other than saying you might be disappointed if you're expecting a significant performance boost. I found something similar a month or two ago where I had a HW initiator available on 3 hosts that were using software. After testing, I found performance to be the same. (benchmark iops/latency)
I'm guessing that if you have extra CPU available in your host, using the software initiator won't hurt anything- especially if it helps make your environment more consistent. Still, I have no good reasons why you shouldn't use the HBA features.
Just for anyone who's interested in this same topic, I actually found a Reference that suggests using software initiator + Jumbo Frame should outperform HBA.
If his tests are truly unbiased, I guess I will use software base, looks like CPU usage shouldn't be a burden.