Well, thats bad! I'm not able to offer much support but can you tell about your setup: how many disks do you use for data? raw or vmdk? In esxi, does it show high cpu usage even when idle? I found the problem: it was made by my multiple tests on this VM. vSphere Client told me to consolidate my snapshots (even if i had no more snapshot); After consolidate, transfers speed is identical to freenas !
Great work jukolaut The installation was done without any difficulty on ESXI 5.1. But performance don't be very high: only 5MB/s with CIFS (same performance as DSM 4.1) In comparaison, FreeNas (aka Nas4free) transfers speed are about 25MB/s in the same environment. I use Microserver N40L for this tests. Have you an idea why is it so slow ?