I was just reading the excellent whitepaper that NetApp just published. The paper is titled “VMware vSphere multiprotocol performance comparison using FC, iSCSI and NFS“. I guess the title says enough and I don’t need to explain why it is important to read this one.
I read the paper twice so far. Something that stood out for me is the following graph:
I would have expected better performance from iSCSI+Jumbo Frames, and most certainly not less performance than iSCSI without Jumbo Frames. Although it is a minimal decrease it is something that you will need to be aware off. I do however feel that the decrease in CPU overhead is more than enough to justify the small decrease in performance.
Read the report, it is worth your time.