Since I'm on a very limited budget, I'm going to try to build a very primitive NAS with the hardware I currently have. I'll be using 6x1TB HDDs, FreeNAS (never used it) and ZFS (also never used it) where 2 of the 6 HDDs will be for redundancy, so if my math is correct about 3.63TB usable (4x 939GB per drive). The computer I have available has an Intel D945PSN board with 4 sATA2 ports (will require a card with extra sATA ports), Pentium D 940 3.2Ghz, 4GB RAM non-ECC (2GB+2GB, it has 4 slots but 2 don't work) and an OEM 500w power supply. Since it will be used only to backup files, It will only be powered on once in a while. So the questions are: 1. Is the computer "good" enough for the job? I read that ZFS requires at least 1GB ram per 1TB storage, is this for storage capacity (in this case 4x1TB) or total storage including redundancy (6x1TB)? I'm not worried about speed for now, only redundancy/safety. I know, I need a better power supply for that 2. Should the FreeNAS run from a USB2 flash drive or from a 7th HDD? And is the ZFS data safe in case the FreeNAS flash drive / HDD fails, or do I need to backup some kind of ZFS index?