New FreeNAS build...few questions

[Aznboy1993]

I am currently in the process of building a new NAS based off of FreeNAS. I have already purchased everything minus the drives. Here is the build list:


CPU/Motherboard: ASRock C2550D4I
RAM: Crucial 16GB (2x8GB) ECC DDR3 1600
HDDs: Seagate 5TB Enterprise ST5000NM0024
Case: SilverStone DS380B
PSU: SeaSonic SS-350SFE 350W
OS Flash Drive: SanDisk Ultra Fit CZ43 16GB USB 3.0
OS: FreeNAS

My plans for the NAS box are:

- Storage pool for media (ripped blu-rays...~10-15GB a piece, need about 10TB worth of storage for this)
- Storage pool for backups (five Windows PCs, one Mac, one openSUSE PC...looking for around 8TB of usable space)

Questions I have:

- What drives should I get? Looking at Western Digital Red 4TB WD40EFRX or Seagate Enterprise 5TB ST5000NM0024 (from Amazon...one of the seller's has promised 5 year warranty)...
- Is it better to have two separate arrays or one big array (since I have two distinct purposes for the box)?
- Best array to run (thinking ZF2)?

Thanks :)

 

[Robert Trevellyan]

- What drives should I get? Looking at Western Digital Red 4TB WD40EFRX or Seagate Enterprise 5TB ST5000NM0024 (from Amazon...one of the seller's has promised 5 year warranty)...
- Is it better to have two separate arrays or one big array (since I have two distinct purposes for the box)?
- Best array to run (thinking ZF2)?

If you scroll down to the questions on that Amazon listing, some buyers have had problems with the warranty because they are OEM drives. Also, they are "Enterprise Capacity", which is weaselly and not the same as "Enterprise". I would (did) buy WD Reds. Make sure you oversize your array quite a bit to allow for growth while staying under 80% full.

One pool or two is a tradeoff between simplicity and flexibility that only you can decide. With ZFS datasets you can easily manage distinct types of data within one pool. There is also the question of one vdev or two, and there are clear guidelines on that, i.e. don't go wider than about 10-12 drives per vdev.

RAIDZ2 is pretty much the default around here, unless you have a specific need for high IOPS. You wouldn't use RAIDZ1 with drives that large, and RAIDZ3 is overkill for most people.

 

[Aznboy1993]

At the moment, I have about 3TB worth of storage and around 6TB worth of media...I have a ton more BDs to rip (10-15GB per BD....that's 266...I think I got around 150 BDs left to go in my collection...I buy maybe a few a month). I'm thinking I need at least 16TB of space and that should be enough overhead for at least another 2-3 years. Think 6 4TB good enough? I heard that not buying same drive/batch is good. Mix (3) WD Reds and (3) Seagate NASes?

I'm thinking one vdev in RAIDZ2 for now. Still learning more about ZFS!

Thanks for the help.

 

[Robert Trevellyan]

Think 6 4TB good enough?

Nope. With RAIDZ2 that would leave you with very roughly 16TB of storage. At 80% usage that's less than 13TB. I think 8x 4TB or 6x 6TB will meet your needs better.

I heard that not buying same drive/batch is good. Mix (3) WD Reds and (3) Seagate NASes?

I'm not convinced this is a great idea. You may lessen your chances of multiple failures but increase your chances of some failures. I bought my drives over the course of a couple of months but I probably wouldn't even bother with that next time.

I'm thinking one vdev in RAIDZ2 for now.

Sounds good.

 

[Aznboy1993]

Gotcha. A lot of invest. Would the 4TB array be better than the 6TB?

 

[Robert Trevellyan]

Would the 4TB array be better than the 6TB?

It depends.

Fewer drives means lower power consumption, statistically fewer disk failures per time period, potentially higher performance (but unlikely to be measurable), lower cost to replace all drives as a method of pool growth.

More drives means higher potential maximum capacity.

Right now 8x 4TB would be a lower cost per usable TB, excluding the rest of the system.

 

[Nick2253]

If you're still considering different drive options, I went with the Seagate 4TB NAS drives (don't confuse the NAS drives with the "Enterprise Capacity" drives; they are different beasts). I chose the Seagate drives over the Reds because of the cost when I purchased them. I bought three from Newegg and three from Amazon to hopefully limit batch problems.

Like Robert, I probably wouldn't do this next time. I'd skip the multiple vendors and just buy them once. Amazon actually shipped them using much better packaging, so that's where I'd get them in the future (but from Amazon, not any other seller).

Theoretically, ZFS works really well with mixed and matched drives. However, slight performance differences between different models and manufacturers may compound to non-trivially reduce performance. Don't forget that, with ZFS, you basically get the lowest common denominator of anything you give it.

 

[Aznboy1993]

Noted. Thanks for the insight, the both of you :)

How is it generally viewed on using non NAS drives? I.e. The Toshiba 5TB PH3500U-1I72

I'm thinking 4TB too small and 6TB too high cost/GB.

 

[Robert Trevellyan]

How is it generally viewed on using non NAS drives?

Non-NAS drives will work just fine, but there are at least two clear benefits to NAS drives:

1. Support for TLER.
2. Longer warranty (within same brand).

 

[Aznboy1993]

I believe that the drive does appear to support TLER. Longer warranty is very true, but I think I will replace the drives within three years. I can get them for $125/ea. + shipping if I go with 6 of them.