cifs frezze/crash when copy from (esxi)

[reks]

Hello,
I'm new and newbie in freenas.
I installed Freenas(as VM) on hp ml110-g05 with esxi.
When i give to freenas 2gb of ram all works fine. But if i give more like 4gb i get problems... When i want copy some file from freenas(movies etc) then after some seconds transfer freeze and with him all cifs (i need restart cifs). Logs are clean. I use zfs, 1x2TB HDD to storage(raw mapped to freenas) and 2x250gb on E200 raid controller - raid 0 to esxi with VM.

Other thing:
Copy to freenas works well
I test much loader.conf and this same
My transfer to and from freenas ~60-90MB/s (differently)


Any ideas?

Regards,
Reks