Some interesting findings from VMWare Unofficial Storage Performance
Some more interesting comments contributed by all the testers:
1) VMFS block size (1-8MB) seems to have little to no effect on performance.
2) Thin/Thick provisioning doesn’t have much impact on performance.
3) RDM has minimal performance increases over VMFS (except in 100% sequential tests which just won’t ever happen in the real world), VMFS has minimal impact on performance, achieving approximately 98%+ of physical performance, so others suggest use VMFS all the way
4. The most real test seems to be the “RealLife-60%Rand-65%Read” – in normal life you have random and sequential connections mixed (often 60% Random vs 40% Sequential).
5. We can see vm on iSCSI compared to physocal server loses more throughput and response time than its counterparts on FC SAN. (but not much <5%, especially in situation of sequential Read/Write)
6. First my suggestion for disabling Jumbo Frames would only be on the Guest O/S. Leave it enabled on the switch and the vSwitch on the host.
7. As for performance best practice, configure VM using Version 7, Paravirtual for Disk Controller and NIC as VMXNET3.
