NIC iSCSi offloading: Experience & feedback

[OIMJB]

Hi,

Is anyone have experience about working with iSCSI offloading in NIC? (think here Broadcom NetXtremeII)

Is it reliable, and is it some performance gain to work with?

@ Starwind team, do you have some recommendations about iSCSI offloading by NIC?

Best regards.

[jeddyatcc]

Unless booting to iSCSI, I have never seen a performance gain from doing this. It is a nice idea, but our performance actually went down considerably when this was configured.

[Anatoly (staff)]

Actually we are totally agree with jeddyatc statement. To be honest I have nothing to add here

[jtmroczek]

I want to echo the above. In almost every real world case I have seen, offloading either did little to help performance or harmed performance.

The few cases where it has helped throughput were machines that were CPU bound. If you have either initiators or targets that often run in excess of 80% cpu time, you may try experimenting with enabling some offload features.

~joe

[anton (staff)]

TCP offload is mature and must be enabled. iSCSI offload should be disabled by default. With modern CPUs it has very little to improve performance and is actually begging for compatibility troubles.