We are using FAS 8020. One of our application requires 40 MB/s throughput on a virtual machine. Ontap version is 8.3 cluster mode We run vertica utility on VM and found only 25 to 35 mb/s throughput. We are using 10k rpm SAS disk and total 22 data disks dedicated aggregate for this task.
We had tuned our Linux VM for better performance like an eager thick disk. Only one VM on single esxi server etc. We have also provided FC RDM lun but expected performance not achieved. Please help us to guide how we can achieve this.
You would have to analyze the bottleneck location and try to resolve it, there's no magic solution that resolves all the possible bottlenecks (actually some flash vendors will dispute this statement :-D)
if you want to troubleshoot it yourself there's a few tools and articles that can help you with it. but i think that it's easier to use NetApp internal skills and tools to at least put you in the right direction. (internal to the array. or external)