Critique My Plan for a NAS Please!

I have many, many large media files on a machine which I use as a media server. Right now, it's a JBOD configuration. I want to build a NAS with 8 GB of storage. I've been researching for a while, but I want to run in by you guys before I start buying the hardware. Basically, I've amassed a large collection of media and I don't want to lose it. Ever. I realize that RAID is not the same thing as a backup, but I think it might be close enough for my purposes. Anyway, here's my plan:

-Buy 5x 2TB hard drives (probably 5400 RMP caviar green)
- Use an older motherboard/CPU/Memory combo sitting around to hook up the drives to.
- Install FreeNAS with ZFS

From what I understand, ZFS is better at ensuring data integrity compared to a RAID 10 configuration, which I was planning previously. Is this true? If one drive fails in the setup I described above, will I be able to replace it with no data loss?

Would I still need a hardware RAID controller if I'm using FreeNAS and ZFS?

The idea is to have this NAS mounted as a network drive on my media server, and from there I'd stream content (hosted on my NAS) to my xbox360 where I could watch it on my TV.

I'm obviously still a bit confused about the whole process, so any clarification would be greatly appreciated.
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  1. I'm not sure the Freenas project has a stable release using freeBSD 8+. There was talk of a beta version but I haven't been on top of things to get a sense of it.

    ZFS zpools are similar to raid 5 in that they can survive one drive failure.

    Your plan seems to be a good one. I have a box which I built to go in my new house but alas, the house project is dragging on.... into the new year. Hope to have electrical roughed in before christmas!
  2. Sorry.. forgot to mention you DO NOT need a RAID controller as freenas is software based. You would only need one to provide more sata ports (and only use pci E for this).
  3. So if it's software-based, wouldn't I need some higher-end processing power and memory? I've always heard software-based RAID is slower and more system-intensive. Is this not true?

    Also, is it true that ZFS provides higher data integrity (longer MTTF) for the disks? Thanks for all the help!
  4. Best answer
    ZFS can be fairly ram intensive. Depends on the number of concurrent processes (ie users). Processing power may limit your read/write speeds but an atom based machine running freeBSD should be able to compete with most of the reasonably priced NAS machines. I think a 3ghz dual core with 4gb ram should be able to max a gigabit connection. Maybe at 2ghz you could get close? The amount of power required for parity and zfs' style of ecc is minimal.

    The data integrity comes from the way the file system writes. It checks to see that what is written is what was intended (hdd level ecc). This is where ram can play a part as it is required for a buffer. The fact is that a 2tb disk will likely have a bad sector or two. It is best to find this out during the write process rather than the read process, or God forbid, the restore from backup process. As volumes get larger the percentage chance of data corruption in a 'regular' RAID 5 is quite large. Zfs helps to mitigate this.
  5. There is a zfs superguru zealot in these forums from whom most of my information is gleaned. Hopefully sub mesa will drop in and add some insight. If you see any sub mesa posts you may find a link in his signature to his own freeBsd... actually it's here
  6. Thanks for all that info adampower. I don't have a gigabit network setup, but perhaps it's time for an upgrade. Since I'd be playing 1080P movies which have a video bitrate of around 10Mbit/sec, I wouldn't expect to have many problems with bottlenecking. I suppose that could be an issue if I'm writing to the NAS at the same time though.
  7. dlink sells the dgs 1008d (8 port gigabit switch) for around 40-$50. If you need to upgrade your nic you can get a good intel nic for less than 40. You only really need to upgrade your server and htcp. The rest can putter along until mobo upgrades.
  8. Best answer selected by davomyster.
  9. Thanks for all the help, but I have one more question. Would 5400 RPM drives be sufficient for this? What kind of difference in terms of read/write speeds would I see? Again, all I'm trying to do is stream HD media to my Xbox 360. I'd also be worried about generating too much heat if I had 5 x 7200 RPM drives.
  10. 5400 RPM drives are made for this. I use wd green 2tb drives mostly (have a couple 1tb and seagate lp 1tb 5900rpm). Anyway, the only 'problems' with them are related to the fact that they are NOT enterprise level drives and are missing things such as tler support. imho thanks to zfs this is not a huge issue for home users. Don't forget to ask about the 4kb sectors when setting up your array.
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