building RAIDZ2, mixing RPMs

[Konrad Gądek]

Hi all. To begin with: this is my first post; thanks for being awesome, been reading these forums for quite a long time, I've learned a lot.

Ok, so to the topic.

TL;DR: shall I expect the higher disk wear because of differences in RPMs on RAIDZ2? Maybe some other disk layout is recommended?

Longer story: I'm willing to build a NAS for my home usage, primarily for backups but also for being a simple data store of multimedia files across few computers in my home. The main goal is data security/integrity, performance is rather unimportant. I try to reuse old components as I have a limited budget. I already have two Seagates (~2 yo with v. low usage) and now I will probably buy 2 or 3 WD Green (will do WDIDLE3 of course).

Since the security is a priority, I assume the RAIDZ2 would be best suited even if I go with 4 disk total, despite the popular recommendation that 4+2 would be optimal. I know I know I know, offsite backup is way better, but this NAS is to be a backup solution already and my budget is already stretched.

The thing is that Seagates are 7200 RPM and WD Green are 5405. I'm slightly worried that due to uneven performance the wear level would not be even and WDs could quickly die. Should I be worried?

 

[hugovsky]

If security is your priority, you need ECC ram(ate least 8GB), RAIDZ-2 and new disks. Reuse of old components is not a good ideia. Greens with wdidle3 are good to go. You should take a look at the "new to freenas?" section, there's lots of good readings there. You can start here.

 

[marbus90]

Newer WD Greens may not support wdidle anymore, so better go for HGST NAS or Seagate NAS. WD Red HDDs don't live up to their reputation in the (debateable) backblaze reports.

Depending on where you live you can get a Lenovo TS140 (5 HDDs) or Dell T20 (4 HDDs), add a Crucial CT2KIT102472BD160B kit and be done for 300-500 bucks before HDDs.

 

[Robert Trevellyan]

The thing is that Seagates are 7200 RPM and WD Green are 5405. I'm slightly worried that due to uneven performance the wear level would not be even and WDs could quickly die. Should I be worried?

To answer your question, no, the difference in RPMs between disks will not impose any additional wear on them.

 

[Ericloewe]

If anything, unusual performance characteristics may result from mixing and matching drive speeds. Nothing I'd really worry about, in most settings.

 

[cyberjock]

Newer WD Greens may not support wdidle anymore, so better go for HGST NAS or Seagate NAS. WD Red HDDs don't live up to their reputation in the (debateable) backblaze reports.

I don't even know where you got those 2 statements from.

A friend owns a WD Green that is less than 45 days since manufacture and he changed it without any problems. wdidle shouldn't be confused with wdtler (which hasn't worked on WD Greens for 4+ years).

WD Red's don't live up to their reputation on a report that defies reason, and despite the fact that craploads of people here use them. I've got 10 6TB WD Reds (bought the night they hit Newegg shelves) and I've had no problems.

Not even sure where you are sourcing your info, but in neither case is their widespread information that validates your claims...

 

[marbus90]

10 is a really small and cute dataset. Statistically worth around 0. I'm doing statistics from 40-60 HDDs of one model and those aren't exactly accurate. This doesn't prove your claim that Reds are worry-free drives. In Backblazes enviroment WD Red NAS HDDs did _worse_ than newer Seagate Desktop HDDs, as you can read here: https://www.backblaze.com/blog/best-hard-drive/
Especially the part "Backblaze Hard Drive Failure Rates, Cumulative by Quarter" is interesting. Don't bother me with the old Seagates, they were crap indeed. Concentrate on newer models, put in service from 2014 on.

As for wdidle, meh. May work, may not. WD can change that any time. When you pay Red prices, the other NAS HDDs are in close quarters.

 

[cyberjock]

So... no link to anything about WD Green, just FUD that it may change at any time. Well, people were saying that before I bought my Greens, and they were purchased before the flood that wiped out a significant part of the manufacturing facilities and cause prices to rise.

No link to anything about the Reds being a bad choice except the same source you provided above (backblaze) which was already discussed months ago and basically signed off as debunk.. for now. Even Backblaze admitted that their sample size for the WD Red 6TB is not sufficiently high to take those numbers and actually use them to determine what is best for your server. In fact, they said they still plan to buy more Reds so they can gather more data.

So nothing of value was posted as a response. Ok, well, I stand by my comments then as they are clearly unchallenged by any kind of facts.

 

[marbus90]

Essentially you're just pointing at Backblaze, saying their 450 WD Reds vs 495 Seagate Desktops sample size means nothing and your 10 disk sample size rules the world, because you see a zero percent failure rate. You just like your personal statistics better. Their 6TB statement was from the time when they had a single 45disk pod deployed with those.

Backblazes chassis design is fairly common. Look around and you'll see other chassis like this. Cisco has a UCS server with standing HDDs, as far as I know iX is working on a similar trueNAS as well, Supermicro offers a 90bay JBOD... vibration? your supermicro doesn't have vibration damping, not even as option.

 

[nick779]

If anything, unusual performance characteristics may result from mixing and matching drive speeds. Nothing I'd really worry about, in most settings.

Just figured Id add to this, I have 4 reds and 2 7200rpm blues in my z2 and its been working fine for months now. My only complaint is that the blues vibrate a bit.

 

[Ericloewe]

Yeah, my single 160GB WD Blue, which used to be in my pfSense box, did vibrate quite a bit. It was amplified by the El-Cheapo chassis, too. Adding an external USB drive on top of said chassis solved that problem. :p

 

[Bidule0hm]

I can add to the stats 4 more WD Reds (3 TB) used with 4 Seagate NAS (3 TB) in the exact same load, temps, mechanical conditions, etc. For now they both offer exactly the same perfs, reliability, etc. excepted that the Seagate are noisier during seeks.

 

[Konrad Gądek]

Thanks for the replies. Good to hear that it should just work. If anything bad happens, I'll report back (hope not).

// Shall I mark question threads as solved? Guidelines/Forum rules do not mention that… or do they?