Making an educated guess (by number of postings), you have not been running FreeNAS for very long. If I'm wrong, then did any previous version of FreeNAS run longer than a week on your machine?
Here's the deal, it's damn hard to troubleshoot a problem with the information you have given us. And trust me when I say we want to help because if it's a real FreeNAS problem, we want to document it and get it fixed, not just for you but for everyone. But we have no idea of your system makeup or if anything else was running. Are you doing something specific when the system crashes? What are all the indications of the failure, to include looking at the console for error information. What is the makeup of your system? Which version (32 or 64 bit) are you running?
As Cyberjock was saying, my first thought would be for you to run a test suite against your hardware to see if the CPU or RAM are failing. If you are overclocking anything, don't. FreeNAS isn't that hungry for speed.
Once you have posted some additional information then maybe we could guide you to a solid solution.
I'll give you a problem I experienced today... I changed my RAM from 8GB (4x2GB) to 16GB (4x4GB) and since my older RAM was running at 1600 speed, and my new RAM could operate at 1600 speed I went ahead and forced it to 1600. Booted the system, it worked fine for a long time, well until I started pushing continuous data (backups) at it and then it crashed. I rebooted and tried again, crashed again. I dropped the RAM back to the default of 1333 and now it's stable, well so far. I have a few days of testing before I can bring it back to the basement where it belongs.
Please don't take anything I have said as harsh, it's just plain hard to work with very little information although I suspect it's your hardware based on what little we know right now.
