Help me decide if this is right...

[Morgan]

First off, the context. I am in a home environment with no real time-critical applications. I use things like Plex, Sickbeard, CouchPotato, etc. I do have some sensitive and critical information, but I think i've already figured out a backup plan for that information for the future.

So i'm thinking about building my first official NAS box. I currently run an Ubuntu box, CLI only, with things like Samba, SB, CP, Plex, etc on it. It has around 10TB of usable space at the moment. None of it has any backups, nor is it raided in any way.

So now i'm at a turning point, and i'm not 100% convinced, but enough that I think i'm going to move forward anyway. I'm here just for thoughts in general.

The box itself contains a Gigabyte GA-870A-UD3 motherboard. I'm not sure on the revision, but from multiple places on the nets they say this board supports ECC, as does the processor i've already got installed. Nice! However I currently am running generic DDR3 with only 4GB, so I ordered 16GB of ECC memory. It was rather spendy.. but from everything I've read it's the only way to go.. However... My board has 6 SATA ports, and I'm still not convinced just using RAID5 isn't as good as ZFS RaidZ1. Thoughts?

Also, i'm using WD Caviar Greens, and this forum is the first i've read that said I should go to Reds? Is that necessary? What are peoples personal opinions on the matter?

Lastly, how many of you go with RaidZ2 instead of 1? I really can't decide... My thoughts are i'll go with RaidZ1 for now, and when 4TB+ Reds go on sale i'll buy a bunch and move to RaidZ2 at that point.

Overall thoughts? I really just need to be sure i'm not going down the wrong path here! Thanks!

 

[joelmusicman]

Motherboard = We were just having a discussion in another thread about motherboard ECC support. Some mfgs may define "support" as "can use the RAM without complaining" but not "can actually use the ECC functions."

Green vs. Red = Absolutely not necessary to replace your existing drives. Just use the WDIDLE tool to change the head parking setting.

RAIDZ2 vs. Z1 = RAIDZ2 is very much preferred. The issue with RAIDZ1 is that if a single drive fails, you then have no redundency, and even a few data errors during the resilvering process can cause the array to fail totally.

 

[Neil Whitworth]

RAIDZ1 vs. Z2 - depends on how much redundancy you need. Only you can answer that one.

If you choose RAIDZ1 you can not switch to RAIDZ2 without destroying and recreating your pool.
If you go RAIDZ2 then 6 drives is a sweet spot for usable space/parity.
You should not expand your pool by adding an extra drive. You need to add enough to keep the redundancy you already have.

See cyberjock's guide for for more details.

 

[joelmusicman]

You should not expand your pool by adding an extra drive. You need to add enough to keep the redundancy you already have.

The GUI is much better in the newer versions of FreeNAS about warning that this is a non optimal configuration. Still good advice though.

 

[joeschmuck]

Joel,
To address your questions...
1) When trying to figure out RAIDZ1 or RAIDZ2 just ask yourself this one question... If my RAID died and I did have all my data on a backup device, how long would it take to load the data. And if I didn't backup certain data, how long would it take me to recover what I really wanted back? For me it was a question like that because I don't feel like spending a few days recovering data, I'd rather spend the extra money on a drive up front. It took me several months to realize it as I was running a RAIDZ1 for a while. Now you could go with RAIDZ1 and if you have a single drive failure, turn off the system and hope that you don't have a second drive failure while fixing the first failure.

2) A RAID5 is not as good as a RAIDZ1. It's the error checking (scrubbing) to weed out bit reversals that make ZFS worth while. This is also a reason you need ECC RAM for ZFS because a memory error will kill your data during a scrub.

3) As mentioned above, you cannot change directly from RAIDZ1 to RAIDZ2 without compromising your data. You would need to destroy your pool and recreate it. The other option would be if you added a new SATA card with 6 ports or as many hard drives as you have, add the new 4TB drives to the new connections, create a new separate RAIDZ2 pool and then transfer your files over. Once done you could destroy the old pool and remove the drives. Lastly you could connect those new drive into the same SATA connections of the original drives and remove the new SATA adapter card. Of course if the SATA adapter card was fast, I'd keep it. The downside to this operation is you need to purchase an card and your power supply would need to handle the extra hard drives, or use a different power supply to temporarily handle it.

4)Never ever never add a single drive to expand a pool! If that drive fails, all your data is gone, even if you started with a RAIDZ2.

5) Green and Red drives are not the same, the firmware is different. It's not a head parking difference at all, plus the Red gives you 3 years of warranty where the Green gives you 2. As for the firmware differences, I can't tell you that in a FreeNAS that you will notice the difference because I haven't heard of one yet but there are some features which I would rather have that the Green doesn't. The main one if vibration dampening where the hard drive can sense vibrations from the entire drive structure and adjust rotational speed to minimize overall vibrations thus allowing longer life. The choice in a personal one to be honest. I told you why I go with the Reds and to be honest, other low cost NAS drives are hitting the streets to compete with the Reds so that is something else to look into (Seagate ST4000VN000).

6) If you are planning to move to 4TB drives within the next 12 months or so, I'd hold off buying any drives until those go on sale. Right now NewEgg has both NAS drives on sale for $189/$184. Not too bad, 35 to 40 bucks off respectively.