Hi,
We usually use Jumbo Frames to maximize the throughput of IP-Based storage systems, for example iSCSI SAN storage. And it has a positive
affect on iSCSI traffic that being transmitted on the network.
The important thing about Jumbo Frames is that you should configure it End-to-End. I mean you should configure it on your VMKernel port, vSwitch,
Physical Switch and finally SAN storage. And setting the Jumbo Frame with just configure the Maximum size of frames and it wouldn't affect traffic
and VMs with lower frames being transmitted.
You can also refer to the following VMware blog post for more info:
Jumbo Frames in vSphere 4.0 | VMware vSphere Blog - VMware Blogs
Hope it helps,
NetRock