Some Hardware advice needed

[jgreco]

I thought Avoton TDW is 20W. Are you adding 5w per RAM stick? Also I've heard 5W per HD.

The TDP of a CPU is not what you use. It can be used as a rough guess as to the required watts, but last I looked, there are other parts on the mainboard, and those take power too, and there are fans in the chassis, and those take power too, and there is an IPMI controller, and that takes power too, and there is RAM, and that takes power too, and drives take power too.

Now, if you're building systems professionally, what you do is you actually go to spec sheets and pull the relevant data. A system with 24 sticks of RAM, or high static pressure fans, or dual CPU's, or lots of drives, you have to very carefully calculate the values in order to make sure you're not going to burn out $10K of parts and have to fix that under warranty. You don't go with something "you've heard." I'll be happy to show you a fan that takes 53 watts all on its own. Typically put like four of those in a case and suddenly you've got to budget 250 watts of PSU just for cooling.

But here, we're kind of talking a relatively small system. I took a few liberties and made a few reasonable assumptions based on several decades in the business. You could still do a rigorous analysis, but the thing that swamps a NAS box is drive spinup current, especially with these SoC boards. And the steps between power supply tiers are large enough that even if I was a little off on that 40 watts, or a few watts per drive, it'd fall into the very healthy safety margin I advocated.

That's why I show people the math, rather than just pulling the number they need out of my butt. My number WILL be good, but the reason you should trust it is because I can show you why. In many cases I overestimate a little, because the harm of overestimating is pretty much zero, compared to the cost of catastrophic failure due to underestimating.

But I also took the 200W cue from this setup
http://www.servethehome.com/Server-detail/supermicro-a1sam-2750f-review-matx-avoton-2x-pcie-slots/

Ugh. You don't just pull up some random website, take a random recommendation, then change some of the key parts, and get to think that this has any chance of being vaguely meaningful. Sorry.

A 200W supply is probably just fine for an Avoton with an SSD or a single HDD. It is likely to be woefully undervolting a NAS box with even just four drives, or, if not, then it is probably sacrificing the longevity of components in the power supply.

 

[madtulip]

Im looking forward to this box arriving. Its my ~10th private PC build over the years but my first custom server.

About the PSU i thought that after so many years of PSU and HDD development i can exspected some brown out detection in the system so that it doesnt corrupt in the case of power shortage. also i thought that the transients of spin on consumption would be handled a bit smarter by i.e. spinning up in series instead of all at once as a standard of modern electronics. but i guess it cant hurt to assume the worst case.

I am still not sure about the L2ARC and ZIL drives and if i should put SSDs for that or if that is just not requirequired for such a small box. If somebody could drop some wisdom about that?

Also what was the keyword about using the 2 Lan interfaces in parallel? I did get the impression that there was some software capable of distributing loads over the individual adapters in case multiple streams connect to the device. Looking at the 2 households and the periods where the NAS would backup or move larger data ammounts it would be nice if that wouldnt fully block other connections to the box.

 

[JJT211]

From what I understand, you wont be messing around with ZIL, L2ARC or anything like that until you've made it to MEGA-Server status and have maxed out your 64GB of RAM and have a crap ton of storage.

 

[Bidule0hm]

Well, all the PSU can do if the mains goes out of specs is cleanly shutoff, and all a HDD can do is stop the I/O and park the heads (and at this point, data corruption is the least of his concerns...). There is no magic trick to avoid this, that's why we use UPSs.

This is called staggered spin-up, the hardware must be compatible and correctly configured for this to work, again, there is no magic trick.

Edit: it's a good idea to assume the worst case, every time for everything in every project, otherwise Murphy will get you... :)

 

[jgreco]

Well, all the PSU can do if the mains goes out of specs is cleanly shutoff, and all a HDD can do is stop the I/O and park the heads (and at this point, data corruption is the least of his concerns...). There is no magic trick to avoid this, that's why we use UPSs.

This is called staggered spin-up, the hardware must be compatible and correctly configured for this to work, again, there is no magic trick.

Exactly this. Brownout detection? Maybe you (madtulip) hadn't noticed, but hard drives are a competitive market. We used to pay many hundreds of dollars for an entry-level hard disk, but now a basic drive is less than $100. The hard drive manufacturers aren't getting those price points by worrying about some geek who's putting ten drives on a machine and is getting voltage sag due to an undersized PSU. That's a real edge case. Power circuitry typically copes with brownout by boosting voltage, which in turn soaks more amperage, which just makes the problem worse anyways.

As for PSU's? With so many years of PSU development, yes, the problem's been "solved", because you can now buy a properly sized power supply, and thanks to 80PLUS you don't need to worry as much about operating a supply inefficiently. They make them in so many different capacities..!

From what I understand, you wont be messing around with ZIL, L2ARC or anything like that until you've made it to MEGA-Server status and have maxed out your 64GB of RAM and have a crap ton of storage.

A SLOG device might be needed depending on what the workload is, but for average needs, it is not.

Also what was the keyword about using the 2 Lan interfaces in parallel? I did get the impression that there was some software capable of distributing loads over the individual adapters in case multiple streams connect to the device. Looking at the 2 households and the periods where the NAS would backup or move larger data ammounts it would be nice if that wouldnt fully block other connections to the box.

Unless you have a managed switch capable of LACP, and enough clients to make the hash average out to an even distribution of traffic, LACP isn't generally useful.

But don't go and race out to buy a managed switch for LACP. Likely you'll be disappointed by how poorly it performs. What I've been suggesting to people instead is getting some used 10GbE equipment like a Dell Networking 5524 and a 10GbE card for the NAS. The 5524's have 24 1GbE ports and 2 10GbE uplinks, are available on eBay, and have gone for less than $300 now and then. A good 10GbE card can sometimes be found for less than $200. I'd say a smart shopper might manage a 10GbE upgrade for the NAS for ~$500. This will be able to slam traffic reliably at multiple clients simultaneously, assuming the NAS itself has sufficient oomph.

 

[madtulip]

Ok thanks. So no SSDs and no LACP for me. Im using Netgear GS116 as main distribution connected to GS105E´s in most rooms. I dont realy see a need here for me to upgrade the infrastructure at this point.

 

[jgreco]

The one thing you could do is to break up your network into two different routed segments and have the NAS on both of them. But it probably isn't worth the effort.

 

[jgreco]

By the way, @JJT211 and especially @Bidule0hm ... and anyone else who's been taking up the slack ... as one of the original tenants of this forum, for awhile ("before Cyberjock") I was one of only a few regular posters answering questions, and it was at times rather depressing. It is totally awesome that especially in the last year or two, we've had a whole new crop of participants, who so often give the answer I might have given, before I'm able to get around to it. It makes this forum very much more enjoyable (at least to me), and I wanted to say some combination of "good job" and "thanks" and "welcome aboard."

 

[Bidule0hm]

Thanks, really, thanks ;)

 

[madtulip]

update: box is working fine so far :)! Thanks everybody!