Multi-Purpose System need input

zdenkers

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Are you purchasing a PSU for this build as well? If so I figure you'll probably spend ~$100 for a PSU as well. If you can go rackmount the 3U supermicro CSE836 series can be had for cheap on ebay and typically have 12 bays for ~$300. That is an additional $100 for more drive bays, redundant PSUs, and a likely better built chassis than the one you posted. In fact, here is one for under $300 which even has a board (though it is quite old and perhaps you'll want to not use it). Here is another with a direct-attach backplane that can be used with 1 HBA if your motherboard has plenty of SATA ports; else you can pick up 1 cheap expander.

Honestly i don't think i want to mess with used psus on a $6000 system lol. But i for 100 extra it seems ok for the extra disk capacity. Though my understanding is that freenas doesn't allow for expanding a raid one disk at a time. You essentially have to swap out the entire array to expand it.

Plus i would prefer to stay 4u just for the sake of airflow and being able to get a decent heat sink for the cpu.
 
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Honestly i don't think i want to mess with used psus on a $6000 system lol.
With many of these chassis you get redundant PSUs and a distributor, I'd bet even used those are more reliable than a single PSU in a system without a distributor.

Plus i would prefer to stay 4u just for the sake of airflow and being able to get a decent heat sink for the cpu.
Plenty of options in the 4U size as well with 24-disk capacity. Honestly though, with the 3u chassis and the high-quality fans you'll have no problem pulling enough air through the case to cool it. In the configurations I'm proposing the chassis fans sit behind the HDDs so air has no choice but to go past the HDDs.

I'm only suggesting it because I honestly think the supermicro cases are a significant upgrade from the one you posted, even used. The case you posted doesn't come with a PSU either so consider the ~120 for the case + ~100 for the PSU and you're not really looking at any appreciable extra cost unless you already have a PSU you plan to use. But, you seem to have a sense of what you need and what you're looking for so I'll leave my argument at this. :)

There was an interesting article or two going around that suggested that humidity, rather than temperatures, had a bigger impact on drive failure so long as temps stayed at or below the medium-high range. What the cutoff was I don't recall.
 

zdenkers

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I intended to install redundant with a distributor all new :) but i am inclined to look at those super micro options because i completely agree they will be far superior to a rosewill chassis lol.
 

droeders

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Are you purchasing a PSU for this build as well? If so I figure you'll probably spend ~$100 for a PSU as well. If you can go rackmount the 3U supermicro CSE836 series can be had for cheap on ebay and typically have 12 bays for ~$300. That is an additional $100 for more drive bays, redundant PSUs, and a likely better built chassis than the one you posted. In fact, here is one for under $300 which even has a board (though it is quite old and perhaps you'll want to not use it). Here is another with a direct-attach backplane that can be used with 1 HBA if your motherboard has plenty of SATA ports; else you can pick up 1 cheap expander.

I couldn't agree more with all of your points except that the Supermicro 3U 836 series have 16 bays rather than 12. The 2U 826 series typically have 12 bays.

I own a used SM 826 and 836 and have been very happy with both of them. I have limited rack space or I would have went with the 24 bay 846 instead.
 

zdenkers

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I couldn't agree more with all of your points except that the Supermicro 3U 836 series have 16 bays rather than 12. The 2U 826 series typically have 12 bays.
Sorry, you're right, I just can't do mental math. :shrug:

It is lacking power supplies; that will add to the cost somewhat but otherwise it looks fine. I bet you could find one with power supplies for around the same price?

So i'm considering this barebones, my question however is whether this backplane will workout with that gigabyte mobo? This is where i start to have very little knowledge is when you start talking about sas backplanes and expanders and such. what else would i need to make this work for the rest of my hardware?
There are several general kinds of backplanes. A typical direct attach backplane is going to have a data plug on the back of the expander suitable for a SAS or SATA data cable. Supermicro typically appends these backplanes with TQ. You can pick up an HBA similar to this LSI-9211 which will allow you to directly attach 8 drives with a cable like this one. You can then attach the remaining 4 drives directly to an HBA with more internal ports, an additional HBA, use an expander, etc. The key is that all of the ports need to be plugged into something.

There is another style of backplane similar to the direct-attach backplane which uses a single SFF8087 for every 4 drives, since an SFF8087 has 4 lanes. For a 12-bay chassis these will require 3 cables plugged into something. A popular option is to pick up an HBA like the LS-2911 from above one and use an expander like this one.

The HBA and expander combination can be used to provide bandwidth for up to 24 drives.

The expander backplanes have an expander built into them and use a single SFF8087 plug to provide bandwidth to all of the drives. Some may have more than 1 plug and are there for cascading, failover, additional bandwidth, etc. These can be powered by a single HBA such as the LS-2911 above so long as it only requires two cables to provide full bandwidth.

The backplane in the case you're describing is the BPN-SAS2-846EL1 you'll find the documentation on that backplane and how to use it here. Keep in mind the documentation includes the info for the EL2 variant. From the documentation

SAS2-846EL1 backplanes have a single-port expander that accesses all hard drives and supports cascading.
. You should be all set with a single cable then in this case.
 
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zdenkers

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Sorry, you're right, I just can't do mental math; 3 columns of 4 is in fact 12 drives. :shrug:


It is lacking power supplies; that will add to the cost somewhat but otherwise it looks fine. I bet you could find one with power supplies for around the same price?


There are several general kinds of backplanes. A typical direct attach backplane is going to have a data plug on the back of the expander suitable for a SAS or SATA data cable. Supermicro typically appends these backplanes with TQ. You can pick up an HBA similar to this LSI-9211 which will allow you to directly attach 8 drives with a cable like this one. You can then attach the remaining 4 drives directly to an HBA with more internal ports, an additional HBA, use an expander, etc. The key is that all of the ports need to be plugged into something.

There is another style of backplane similar to the direct-attach backplane which uses a single SFF8087 for every 4 drives, since an SFF8087 has 4 lanes. For a 12-bay chassis these will require 3 cables plugged into something. A popular option is to pick up an HBA like the LS-2911 from above one and use an expander like this one.

The HBA and expander combination can be used to provide bandwidth for up to 24 drives.

The expander backplanes have an expander built into them and use a single SFF8087 plug to provide bandwidth to all of the drives. Some may have more than 1 plug and are there for cascading, failover, additional bandwidth, etc. These can be powered by a single HBA such as the LS-2911 above so long as it only requires two cables to provide full bandwidth.

The backplane in the case you're describing is the BPN-SAS2-846EL1 you'll find the documentation on that backplane and how to use it here. Keep in mind the documentation includes the info for the EL2 variant. From the documentation

. You should be all set with a single cable then in this case.

I think the backplane would not be compatible with this mobo since it only has slimlineSAS connectors. also my understanding is that i would be limited to the bandwidth of 1 sas connector, that seems problematic. that being said i think to avoid backplane nonsense, https://www.amazon.com/dp/B00N9CXGSO , its also a rosewill gives me 12 hotswap bays. which honestly is probably more than enough for if i decide to use a couple extra bays. It does simple sata passthrough and powers off molex. i think i will probably go this route and upgrade the fans.
 
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I think the backplane would not be compatible with this mobo since it only has slimlineSAS connectors.
Sorry, I don't understand. If you pick up the HBA that has the SFF8087 plugs and the backplane has SFF8087 plugs they are perfectly compatible, no?

also my understanding is that i would be limited to the bandwidth of 1 sas connector,
Perhaps, yes. This is where the bandwidth really matters. 1 SAS2 lane has 6Gbps, there are 4 of them per plug; that is 24Gbps. That is ~125MB/s per drive, which should be enough. I think it will be rare that ALL of the drives will be pushing more than that at the same time. You could look for a backplane which supports SAS3 if you're worried about it, you can find those online as well, and pick up an HBA which also supports SAS3 and then you're way above what you need at 48Gbps.

Of course you should do what you're most comfortable with. I found SAS to seem very complicated at first but the quality of the chassis pushed me toward it and with a bit of research I am very glad I did. I bet at 260 for that case plus two PSUs plus a distributor you're well over what you could pay to get a quality SAS3 backplane in a supermicro case off ebay that includes the PSUs and power supplies.

Definitely a worth while discussion and thought to have though before you decide on your final case.
 

zdenkers

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You're probably right. i just want to make sure i don't bottleneck the array because i was being cheap lol. and i also don't want to have extra unnecessary complexity that causes difficulty. but i will keep the sas3 846 chassis in mind.
 
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You're probably right. i just want to make sure i don't bottleneck the array because i was being cheap lol. and i also don't want to have extra unnecessary complexity that causes difficulty. but i will keep the sas3 846 chassis in mind.
Totally fair point. I think I'd feel similarly about bandwidth, even if it likely isn't an issue I'd MUCH rather be in a position where my network was 100% my bottleneck; SAS3 will certainly give you that. :) Maybe you'll get lucky and find a nice cheap SAS3 one.

I actually recently bought a new-to-me chassis and got too excited and pulled the trigger without looking closely enough. Its a SAS1 backplane! I'll probably be spending another chunk to upgrade that backplane before too long. :(
 

zdenkers

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Totally fair point. I think I'd feel similarly about bandwidth, even if it likely isn't an issue I'd MUCH rather be in a position where my network was 100% my bottleneck; SAS3 will certainly give you that. :) Maybe you'll get lucky and find a nice cheap SAS3 one.

I actually recently bought a new-to-me chassis and got too excited and pulled the trigger without looking closely enough. Its a SAS1 backplane! I'll probably be spending another chunk to upgrade that backplane before too long. :(
BPN-SAS3-846EL2 https://www.supermicro.com/manuals/chassis/4U/SC846_JBOD.pdf


So just want to make sure i understand correctly. This backplane uses 2 sas3 expanders, and would thus support up to 96Gbps? since each expander is sas3 and should support 48Gbps? Sorry i'm just trying to determine which supermicro 4u chassis fits my needs best. essentially i want to have freenas compatibility out of the box and enough bandwidth to support up to 12 6Gbps drives. Ideally it would be able to support all 24 drives at full speed for future expandibility, but i'm pretty sure thats not possible with a backplane that isn't direct attach?
 

drinking12many

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https://www.supermicro.com/en/products/chassis/4U/846/SC846BE2C-R1K03JBOD Looks like a nice chassis pretty similar to the one my supermicro has but mine is SAS2. As far as double the bandwidth everything I found says it depends on the expander.
For example the SAS2 line
BPN-SAS2-EL1 : 1 chip, just 4 lanes, no dual linking at all
BPN-SAS2-EL2 : 2 chips, 8 lanes but only for failover (with SAS drives only). So no dual linking at all
BPN-SAS2-846EL2 : 2 chips, 8 lanes supporting dual linking. The chassis reference provided by SM is 846BE26-R1K28B

By looking at the link above it appears to only use the extra port if you have dual port SAS drives and not SATA.

"24-port 4U SAS3 12Gbps dual-expander backplane, support up to 24x 3.5-inch SAS3/SATA3 HDD/SSD (secondary expander port only connects to dual-port SAS devices, single-port SATA will not have this redundancy feature) "
 

zdenkers

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https://www.supermicro.com/en/products/chassis/4U/846/SC846BE2C-R1K03JBOD Looks like a nice chassis pretty similar to the one my supermicro has but mine is SAS2. As far as double the bandwidth everything I found says it depends on the expander.
For example the SAS2 line
BPN-SAS2-EL1 : 1 chip, just 4 lanes, no dual linking at all
BPN-SAS2-EL2 : 2 chips, 8 lanes but only for failover (with SAS drives only). So no dual linking at all
BPN-SAS2-846EL2 : 2 chips, 8 lanes supporting dual linking. The chassis reference provided by SM is 846BE26-R1K28B

By looking at the link above it appears to only use the extra port if you have dual port SAS drives and not SATA.

"24-port 4U SAS3 12Gbps dual-expander backplane, support up to 24x 3.5-inch SAS3/SATA3 HDD/SSD (secondary expander port only connects to dual-port SAS devices, single-port SATA will not have this redundancy feature) "


So i can find that BPN-SAS2-846EL2 backplane used, but that chassis seems i can only find for rediculous prices 1300+. If i were to buy any 846 chassis could i swap the backplane? or would i run into distributor issues in getting proper power to everything?
 

drinking12many

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The main problem is the SAS drives having the dual ports won't help you at all on any of them it sounds unless you get dual-port SAS drives to get the extra bandwidth. Though some articles make it sound like if you use 2 HBAs you might get the dual bandwidth but I personally find this dubious because then it seems using two ports from the same HBA should do the same thing. I'm sorry I am not an expert in this area, in the past when I have bought storage arrays we evaluate them on the whole and don't quite get into that level of detail. If a vendor said it supported 2 controllers though in a cluster that pretty much ensures they mean they were dual port SAS aware/functional.
 

zdenkers

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The main problem is the SAS drives having the dual ports won't help you at all on any of them it sounds unless you get dual-port SAS drives to get the extra bandwidth. Though some articles make it sound like if you use 2 HBAs you might get the dual bandwidth but I personally find this dubious because then it seems using two ports from the same HBA should do the same thing. I'm sorry I am not an expert in this area, in the past when I have bought storage arrays we evaluate them on the whole and don't quite get into that level of detail. If a vendor said it supported 2 controllers though in a cluster that pretty much ensures they mean they were dual port SAS aware/functional.

Thats kind of the feeling i get about these back planes is that they tend to be incapable of saturating drives. A sas3 backplane with two ports can do 96Gbps for 24 SAS3 drives. but 24 sas3 drives could technically push 12Gbps each well beyond the 96Gbps capabilities of the backplane. It leaves one to wonder why they would even exist? it seems much more economical and performant to do passthrough, assuming that your mobo supports that level of expansion. but with the price of drives being basically the same per GB regardless of size that isn't much of a problem imo.
 

zdenkers

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So i think i am going to end up with this backplane https://www.amazon.com/Supermicro-BPN-SAS3-826A-N4-Backplane-SATA3-devices/dp/B00U6USYQQ And 8 seagate 7e8 8tb drives. i can get an 826 chassis with other goodies for a pretty good price to go with it, ends up being cheaper than a new rosewill and should be a better overall solution. problem i have now is finding 2U cooling that will perform for a 180w tdp processor.

Any concerns with the backplane for freenas and any suggestions on 2u cpu coolers?
 

drinking12many

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