XigmaNAS

I just bought 5 Seagate NAS HDD 4TB ST4000VN000 and have a few doubts on how to prepare the NAS4Free system:
1) Should the system be RAIDZ1, RAIDZ2, RAIDZ3 or plain mirror (RAID1) ?
2) How much RAM?
3) Is it mandatory or advisable to use ECC RAM?
Thanks

1) Raidz2.
2) At least 8GB, better 12GB, better yet 16GB, best lots of them....
3) Mandatory if you care about your data.

if you choose a MOBO that does not support ECC be sure to run the memory test
I have not built a N4F with ECC but I have checked the RAM before using the N4F
with out ECC do not use hardware or RAM that is in any way less than 100% good
use recommended clock speeds. it has to be error free, as it is not error correcting!

if you are going for new hardware or older server grade hardware ECC RAM is a bit of extra insurance

one should never try to build a N4F with less than perfect hardware
For example one of my son's cast off MOBOs is shown here and seems to work fine. [evga z68]
http://www.youtube.com/watch?v=bcfeRPWCBWM
cast off as a gaming board for memory related crashes. [he kept the i7 and ram]
[It is now my daughters Ubuntu back up desktop]
because despite seeming to be OK 99.9999% of the time
I did not trust it 100%
and it would be a bit of overkill for the job