Thanks for such a quick responce! I've decreased the RAM. In the UI for MineOS it is now showing its using 5000 of 4096 Mb of RAM. Is this going to be an issue?
My Java version is 7u79-2.5.6-1~deb7u1
I have 2 Xeon E5410's. 2.33 GHZ, 12Mb cache, 1333 Mhz FSB...