Hi,
Im thinking about building my personal NAS(wanted to buy at first one like qnap or similar) but got some concerns regarding data integrity and finaly ended here. First of all, im totally green in this, no programing or linux exp. But hard times wont let me think about turning back. So some questions:
1. After reading some articles i found out that safest way would be to go for ecc memory. now the problem with this is that i could not fint any info on what specific system configurations ecc actually works as supposed to. My closest call was Intel® Server Board S1200KP + Intel® Core™ i3/Intel® Xeon® Processor E3 but problem with integrated video(needs processor with integrated Graphics?). So a)will it work with full ecc support using i3 proc, b) would it be better to use E3 with integrated graphics? For me ecc is priority.
2. Could not find anyting from opteron range, my intentions are to use no older then ddr3, support and reliability wise, thus options are limited. Are there any good opteron configurations with full ecc ddr3 support, second G pcie 8x socket and preferably 2xGbE ports?
3.What differnce it makes Sata2 vs Sata3, in performance? Id rather go for faster, but whats the differnce?
4.Better to have more ports in HBA or split them between HBA and Motherboard? ps: i have read about quality of chipsets so other then that no prob?
5. If its HBA do i need to fix firmware or will it work out of box as intended?
6. Intention was to choose something between Seagate or Hitachi hdds 3TB versions(would go for best of thebest - Samsung, but its KIA now). Hoping Seagate is using Samsung design for thier new hdds, with heads parked in spec slots, not on the platters, no info on Hitachi at all. Any ideas?
7. When started, before even finding guru, i found out, that linux based NAS enclosures sold ready to go have one major problem with most of eco hdds, checking discs every 30s o so(OS feature), and those eco models spin down and/or turn of after about 20s, so we get very high start/stop count, whitch may lead to early retire if hdd. How it works with FreeBSD and ZfS guru? (problem noted was with non server WDs Green line, and some others, cant remember, WD is aware of the problem but... money.
8. Intention was to build system with about 14-16 hdds using zfs2 or zfs3 raid. now there is best config for zfs issue, and there was like 3-5-7 for zfs1 and 4-6-8 for zfs2. Now a)What about larger numbers of zfs2/3? b)What would be optimum for that quantity? I dont want to play with 3 5hdds raids of zfs1. Im opting between 1-2. Not gonna use less than zfs2.
9. Is it possible to install all for green person, or should i think about getting some help from the side?

Current ideas:
Intel® Server Board S1200KP (Intel® Server Board S1200BTL option, not sure if i need it)
Intel® Core i3/Intel® Xeon® Processor E3 (no idea regarding model yet)
a).LSI SAS 9201-16i, 16 ports internal, PCIe 2.0 (perfect for me, sata3)
b).HighPoint DC7280 Data Center HBA 32x SATA/SAS (if would want to expand, sata2???)
Seasonic x760 PSU (idea was 460 fanless at first)
Fractal-design Define XL USB 3.0 Black Pearl (10x internal hdds)
Netstor
a).NS160S
b).NS170S (would use sas but sas is for 4 sata only, not sure about cables with this one)
other hdds internally in 5.25 simple mount, no idea yet
Ram still no idea yet

As of Amd...
Would be the same, but proc - mob configuration unknown
Hope to build and have it working in less than 6mon. Use - video/photo storage.
Thats about it. Thank you in advance.

Thank you for reply.
Ill try to post in the same manner:
1. Intel platform (server) has 3 chips, C202, C204, C206. If i got it correctly, C202 and C204 have integrated gpu into chipset, and with C206 gpu works only with processor, that has gpu integrated in cpu. My selected motherboard has C206 so i need E3-1235,1245,1275 etc. Only server processors support ECC. Asus P8B WS might be an option if i can find out ECC support. Now its like x-files, im still looking for the truth. As of motherboard itself, i dont think it is good ideai to save money on hardware, that will handle 18TB+18TB(8x3TBzfs2+8x3TBzfs2) - 36TB of data in total. There is an article on that http://storagemojo.com/2007/09/19/cerns-data-corruption-research/
After reading this, i dont want to save anymore.
2. ECC is cheap, compared to some OC memory, and 2 LAN connections are good if you connect one directly to computer, other one to router.
4. More cards, more power, and price is less per port for big ones.
7. WD green line is off limits, killer of NAS. But other brands are not bad, and if not constantly used, im not sure if there will be any problems with lower rpm. And none non enterprise hdds should do well, but how many of us are using them? My mind tells me that at least in theory lower rpms are better for vibration dampening, if performance is not the key (im my case its not, ECC is not for that). Maybe a mix of them would go better, in separate zfs, of course.
8. You are right on point here, thou i would like 10x3TBzfs2+10x3TBzfs2 way more, but there is no space for more, and i would have to use sata2in motherboard.
9. I was given an impression that it uses more hdds, not ram. And since its not real RAID card, and has freeBSD firmware and drivers, there should be no problems, me thinks.

I only do raid 10 (zfs mirrored pairs striped together). The speed is much better if you have more than one thing going. Rebuilds and upgrades are super fast.

I've never done 4tb drives, but I have a ton of 3tb seagate ST3000DM001-9YN1 doing just fine.

In one setup, I have two istar 5in3 hot swaps that put 8 of those drives to an LSI hba for my pool, the other 2 drives to the mb sata for the install pool, and pool zil and l2arc ssd also to mb sata. consumer (but nice) asus mb, 24gb ddr3 non-ecc ram, onboard realtek for lan, intel nic for nfs san. All fits nicely in an antec 900 case. I don't know if this is perfect, but it works pretty damn good. smb sharing for a bunch of people as well as vmware nfs shares for over 10 vms (all constantly used). If you don't get a case with hotswap built in (norco, supermicro, chenbro, etc...) I really like the antec 900/1200 with the istar bays. You can also use a 6in1 2.5" istar for the ssd and still have two slots left over.

Im in my final run now, but i found one interesting question, that has not been answered yet. Its in post by stefan, where CIPHER gave interesting answer: CiPHER wrote: Why do you need to shutdown? A reboot means the harddrives keep spinning and are powered.

Or did you mean a hardware update instead of ZFSguru update? Are your disks using spindown now, or did you use it in the past?

In datacenters, disks that have been spinning for a long time and suddenly get powered off and later on again, sometimes do not survive this sudden change. Is this what you are afraid of? In most cases, desktop/consumer harddrives are designed to more frequently spin up and down. But i still think there is truth in it: every sudden change is a (minor) risk. Well im thinking now how to avoid getting in situation like this, so i started thinking about my choice of hdds. I originally wanted to use WD Caviar Black WD4001FAEX 64MB 4TB, but i found out that i can get Western Digital RE WD4000FYYZ 4TB 7200 RPM 64MB for the same price. An obvious choice would be to go for RE version, but this particular answer confused me dearly. I have never intended to use nas 24/7. Would home hdd be better in this case?

Im familiar with green wd issue, and yes, 5K4000 low rpm looks nice, sad, but 7K4000 is much cheaper at my location so no point buying 5K4000 for the price of WD RE. And WD Black is practically the same price, with 5year warranty versus 3 of Hitachi and when you calculate price per year wd is cheaper, so i think i will benefit more with wd, and price of RE version does not differ very much(16%) at the moment. So just like i mentioned before, im interested in case of hdds, when its on and off and then its dead.

you could also go for a USB dvdrom. Have one myself and is just awesome as I don't use optical that much myself anymore it is kind of handy when you can use it on multiple machines when needed.

Final count: im filling it now, so ill just write a summary.
CPU working ok, just without power control - OK
MB SAS works, chips too hot for my taste - OK
RAM works - OK
CPU cooler (message: cpu temp - low...)total overkill, but cools the ram too - HAPPY
HDDs 512 format RE, hotter then average hdds, but works good - OK
CASE metal weak, but best hdd mount i have seen+6x140fan option, but with front doors closed, fans max hdd top temp was 46C, door removed - top 40C, fan door open - top 38C - err, NOT OK, err BAD.
It seems Fractal never put all hdds in their cages, and those big fans are just for decoration - avoid, if not ssd or samsung user. I have bottom fan removed, back fan is bequiet silent wings 2 model - silent arctic cooling did not have 140mm pwm. Instalation had to be done using VM, by less green user. Hdds were formated in 4k (how did i miss that one?). In zfs2 config had 20.7TB starting bonus. Note: had to cut corners for intel cpu mount on a backplate - supermicro has very strict parameter restrictions.