Help me build a small JBOD DAS

C

Clickinaway

n00b
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Mar 26, 2013
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:eek:

I know, I'm sure this is getting to be a tired topic, but I've done a lot of research over the last few weeks trying to determine what storage configuration. I think the important thing to keep in mind is this is mostly for educational purposes and fun only.

Project objectives:
  • Cheap
  • (ideally) low-energy
  • (ideally) small form factor (2U or less)
  • rack-mounted solution
  • no mobo/CPU etc.

Project Parameters:

Now, this is where the complete ignorance will reveal itself (if it hasn't already):
-In the JBOD chassis, how are the drives 'exposed' for external connectivity? Via SAS Expander, or some kind of backplane? The first seems overkill and I have no idea how its seated w/o a mobo.
-Recommendation on a cheap chassis(remember I'm not going large here, just doing proof-of concept stuff)
-Because we're talking about mini-SAS connections (i'm kicking myself for even asking this:rolleyes:) does this preclude using SATA drives in the actual JBOD array? (I'd prefer not to have to go eSATA for this reason).

The ultimate outcome of this would be then to test the DAS storage exposed as an iSCSI storage pool through the host or who knows. I'm not trying to start a debate about that. Once the environment is built I can test-break-morph from there.

I hope that's enough to start with. Thanks in advance!
 
http://www.amazon.com/Rackmount-Server-Hot-Swappable-RPC-1204-Connector/dp/B002AU3NVQ/ref=sr_1_29?s=electronics&ie=UTF8&qid=1364318176&sr=1-29&keywords=rackmount+mini-sas

So i've been having poor luck for the reason above. That's not a bad start because with the hot-swapable case I get my mini-sas connect. The 2U 8 drive Norco is close as well. Problem being that there would be so much wasted space here w/o the motherboard.

Can someone point me case that is closer to what i'm looking for?
In the above case, (aside from the PSU and the SM controller board) I presume I'd just need some external SFF sas port, correct? If so can someone recommend something that would work an existing chassis/IOshield?
 
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Thanks for that...aware of them but the front input is a deal breaker. I really need to know about exposing the drives externally and could really use some help in that department. Feel free to flame. I have seen some units real close to what I need at $300, but feel I could do better, at least on the jbod, by rollin my own.

Help?
 
Clickinaway said:
host controller will control RAID etc something like this:
Click to expand...
I've never heard of that brand. Plus the price isn't low enough IMO to justify going with an unknown company IMO. I'd look at the areca ARC-1320-4i4 instead.

Clickinaway said:
Now, this is where the complete ignorance will reveal itself (if it hasn't already):
-In the JBOD chassis, how are the drives 'exposed' for external connectivity? Via SAS Expander, or some kind of backplane? The first seems overkill and I have no idea how its seated w/o a mobo.
Click to expand...
You mainly connect them externally via SAS expanders or SAS controllers. So in other words, you would have a SAS expander in the JBOD chasis. You would then connect the SAS expander via a SFF-8088 to a SAS controller in your main PC.

Now if you're wondering how to power that SAS expander in the JBOD chasis, read this:
http://www.servethehome.com/sas-expanders-build-jbod-das-enclosure-save-iteration-2/

Now the more commonly recommended SAS expander here on the forums as well as Serve The Home is the HP SAS Expander:
HP SAS Expander
Clickinaway said:
-Recommendation on a cheap chassis(remember I'm not going large here, just doing proof-of concept stuff)
Click to expand...
If we're talking ATX, the NZXT Source 210 Elite would get my vote. Fits 8 hard drives out of the box, costs $55 from Newegg, and can fit an additional 4 drives via a cheap 4in3 module.
For rackmount style cases, maybe the NORCO RPC-270 might do the trick.
Clickinaway said:
-Because we're talking about mini-SAS connections (i'm kicking myself for even asking this:rolleyes:) does this preclude using SATA drives in the actual JBOD array? (I'd prefer not to have to go eSATA for this reason).
Click to expand...
No you can still use SATA drives as long as you use the correct cables. For most SAS controllers these days, you just get SFF-8087 to Multi-lane SATA Forward Break-out Cables. Something like this:
$15 - 3ware SFF-8087 to Multi-lane SATA Forward Break-out Cable

What $300 options have you been looking at? If they're actually setup correctly, rolling your own isn't gonna be cheaper. Especially considering that the HP SAS Expander costs $300 by itself.
 
Thanks for the very thorough response. I guess I need to be clarifying a specific point of my envisioned build.

My understanding is that the power controller card removes the need for having any mobo in the jbod case. http://www.servethehome.com/supermicro-cse-ptjbod-cb1-jbod-power-board-diy-jbod-chassis-made-easy/

Therefore, i don't see how the sas expander is used in that application...after all, when you look at jobod cases they dont have a sas expander or motherboard. And this is part of they mystery for me: do they use a back plane (yes for hot swap) or just cabling. My biggest question is what interface do I use to have an external mini-SAS port on the back of the chassis which connects to the drives in the JBOD?

So, if my JBOD doesn't have a SAS expander, doesn't have a motherboard, and I have access to a pile of large SATA drives...I feel pretty confident that my JBOD will be quite affordable.

That all said, I will heed the advice regarding the unknown host controller.

My only beef with that particular Norco is that its full depth so w/o a mobo there would again be a ton of unused space.

Any further thoughts on this? I'm starting to get excited about the project.
 
all the power board does is act as a switch to supply power to case fans and drives.

This leaves two choices - lots of loose SATA cables or another PSU and a mobo to host an interface card of some description.

In the original configuration the powerboard is used to power a dedicated backplane which has a hba built in... you without that you need a motherboard to host the interface card.

http://www.supermicro.nl/manuals/chassis/3U/SC933.pdf have a look at page C-20 onwards for the use of the powerboard
 
Clickinaway said:
My understanding is that the power controller card removes the need for having any mobo in the jbod case. http://www.servethehome.com/supermicro-cse-ptjbod-cb1-jbod-power-board-diy-jbod-chassis-made-easy/
Click to expand...
Again, true about not requiring a mobo. However, you still need a way to power the required SAS expander or SAS controller. And that's where my earlier link came in (the parts about the PCMIG):
http://www.servethehome.com/sas-expanders-build-jbod-das-enclosure-save-iteration-2/

Read the above link very thoroughly.
Clickinaway said:
Therefore, i don't see how the sas expander is used in that application...after all, when you look at jobod cases they dont have a sas expander or motherboard. And this is part of they mystery for me: do they use a back plane (yes for hot swap) or just cabling. My biggest question is what interface do I use to have an external mini-SAS port on the back of the chassis which connects to the drives in the JBOD?
Click to expand...
JBOD cases like this Norco uses a backplane that's connected to a SAS expander. As I said earlier, then the SAS expander is connected to the SAS controller via an external cable using the SFF-8088 interface. Again, what JBOD setups have you been looking at that don't have a SAS expander?

EDIT: Wait are you talking about JBOD cases that like this Sans Digital?
 
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@asgards thanks a bunch!!! Heck yeah...so I may be close to finalizing my parts list.

So it would appear that if i'm all good with having a bunch of cables in the case I don't need a backplane (unless one comes for a hotswap case), motherboard, nor do i need a SAS expander. This is starting to sound very promising! I will edit or reply to this thread with a more refined parts list for review.
 
Clickinaway said:
http://www.netstor.com.tw/_03/03_02.php?Mjk=
http://www.pc-pitstop.com/sata_enclosures/satae41u.asp
Click to expand...
Ahh that's what you were talking about. Yeah the first enclosure just uses the SFF-8088 to SFF-8087 adapters that asgards linked to. The SFF-8087 are for the backplane which is where the hard drives are connected to. The second just uses a SATA to eSATA adapter IIRC. You really only need a SAS expander once you go above 8 or so drives as it becomes very cost-effective then.

Clickinaway said:
We're talking about the same power card, right? Not the one from the DIY....
Click to expand...
No we're not. I'm talking about PCMIG which is used to power cards like a SAS expander. You're talking about a Supermicro board that's essentially used to turn on the PSU and system.

Clickinaway said:
What about the external port on the chassis?
Click to expand...
Depends on which adapter you use. Some uses SFF-8470 while some uses SFF-8088. More common one is SFF-8088.
 
I'm really thankful for all of the feedback. I see exactly what you mean about the cost savings when you step up past a certain number of drives as the various cables and adapters will add up quick. Funds will be mostly dedicated to the controller card which will reside within the host.

I may still be having delusions of grandeur here, but there looks like real potential for me to hit my personal cost goals!
 
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