qlogic hba settings for esxi server connected to vmax

The recommendations are to leave them at defaults. The only parameter that EMC recommends to change for VMAX on ESX(i) is when a customer is using VMware NMP, they should change the PSP to Round Robin and alter the I/O Operations limit from 1000 to 1.

Doesn't that put a lot more work on the CPU to switch HBA's on every I/O?  I thought that the performance gain was negligible compared to the extra work on the CPU.

Yeah there is increased CPU utilization on both the ESX(i) CPU and FA CPUs and the trade-off may not be worth it in all cases, you get the biggest performance increase with large-block sequential workloads where the change is worth it. Other situations may not. We wrote a white paper on this setting with test results etc...

http://www.emc.com/collateral/hardware/white-papers/h8119-tuning-vmware-symmetrix-wp.pdf

In general we recommend changing it, but it isnt a hard and fast rule--and not a requirement.

Thanks Cody.

Thanks Cody.