External SAS Storage 101 (Query not guide)


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Hi all,

 

External storage is a bit new to me, but i've been absorbing as much as i can, as i need to implement a solution (as cheap as possible, because this cost was not planned for) next week at the earliest. I'd like to confirm my understanding and if i've understood right, awesome! If i've got it wrong, i look forward to having a config specific to me, critiqued.

 

So, inside the enclosure we have 8 3.5" HDD's. Would i place an IBM M1115 (i already have this, so more cost effective to reuse than but an 8i8e card) with 8087-Sata breakout cables connect the HDD's to it.

Would i then also add a Dell H200E 2x External SAS inside the enclosure, to allow me to connect the enclosure to the server. (using 8088-8088 cables?)

 

Inside the server i add another H200E External SAS to accept the connection from the enclosure, and that is all that is required in this scenario?

 

Rudimentary ASCII Diagram of proposed configuration....

__________________________________________________________________________________________________

                                                                          /

unRAID Server(H200E)-----------(8088 Cables)----------| (H200E)

                                                                         |         

                                                                         |---Enclosure (mATX MB, Celeron, 4GB, USB Boot Linux OS)         

                                                                         |         

                                                                         | (IBM M1115)---------(Breakout Cables)-----------(4x 3.5" HDD's (x2))

                                                                          \

__________________________________________________________________________________________________

 

If the above is all correct, what are the computing requirements of the enclosure? Obviously i need a MB with 2 x8 PCIe lanes, but is there anything else i need to consider? At present, to keep costs down i'll be reusing a mATX motherboard w/ Celeron processor & 4GB RAM for the Enclosure 'brains'.

 

Is there some sort of affordable Single Board Computer that is commonly used for this task that requires no OS?

 

Appreciate any and all feedback given :)

Thanks in advance!

Nasha

 

EDIT:

 

Proposed correct config by johnnie.black

 

__________________________________________________________________________________________________

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯\                                        /¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯\

unRAID Server(H200E) |----------(8088 Cables)----------| (SAS Expander w/ Int. & Ext. Ports)---------(Breakout Cables)-----------(4x 3.5" HDD's (x2))

____________________/                                       |  ^^ Models of SAS Expander with Int. & Ext. Ports YTD.       

                                                                          |---Enclosure (mATX MB, Celeron, 4GB, USB Boot Linux OS)         

                                                                           \______________________________/

__________________________________________________________________________________________________

Edited by Nasha
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2 minutes ago, Nasha said:

So, inside the enclosure we have 8 3.5" HDD's. Would i place an IBM M1115 (i already have this, so more cost effective to reuse than but an 8i8e card) with 8087-Sata breakout cables connect the HDD's to it.

Would i then also add a Dell H200E 2x External SAS inside the enclosure, to allow me to connect the enclosure to the server. (using 8088-8088 cables?)

No, that won't work, you need an HBA on the server, preferably one with external outputs, then a SAS expander on the enclosure.

 

Alternatively would could connect from the HBA directly to the disks on the enclosure with breakout cables, but cables from HBA to disks will be more vulnerable and can't be longer than 1 meter.

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8 minutes ago, johnnie.black said:

No, that won't work, you need an HBA on the server, preferably one with external outputs, then a SAS expander on the enclosure.

  

Alternatively would could connect from the HBA directly to the disks on the enclosure with breakout cables, but cables from HBA to disks will be more vulnerable and can't be longer than 1 meter.

H200E External on the server....

And i am connecting from the HBA (M1115) directly to the disks with breakout cables, inside the enclosure.

 

Do i need an expander if im using an HBA with breakout cables to direct connect?

 

My understanding, an expander would allow me to run 16/24 disks without altering the hardware?

Edited by Nasha
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2 minutes ago, johnnie.black said:

And how would you connect the H200E to the M1115? You can't connect an HBA to another.

This is why i am here - I had assumed that they could communicate across the PCIe BUS.

 

Ok, so that setup does not work. So i need an HBA with internal & external ports in the enclosure (Examples of such?, i couldn't find anything i'd trust to work on eBay)?

Edited by Nasha
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24 minutes ago, johnnie.black said:

you need an HBA on the server, preferably one with external outputs, then a SAS expander on the enclosure.

 

24 minutes ago, johnnie.black said:

Alternatively would could connect from the HBA directly to the disks on the enclosure with breakout cables, but cables from HBA to disks will be more vulnerable and can't be longer than 1 meter.

 

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1 minute ago, johnnie.black said:

 

 

So option 2 i wouldn't consider - As you said, vulnerable, and 1m limit will make things difficult or impossible.

 

I have an HBA in the server, with external ports, so i assume you are saying i need a SAS Expander in place of my M1115?

 

Can you give some examples of a SAS Expander that has both internal and external ports? I was unable to find anything on eBay with the exception of a SuperMicro UIO card.

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You can use something like this (click to expand):

 

atxsas.thumb.jpg.15f3b2d9643e8f158fba158f1f8d8deb.jpg

 

Adapter from 8088 to 8087, then an internal 8087 to 8087 cable to the expander.

 

There's also the HP Expander, but it only links @ SATA2 speeds max and only a single external port, so around 1100MB/s max for the 8 disks, which can bottleneck a little but it's still a decent speed, could be a bigger bottleneck if you add more disks in the future.

 

image.png.a975d167eb75f782409941eb52a41962.png

 

 

 

 

Edited by johnnie.black
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Firstly johnnie, thankyou very much for your assistance and your patience. This concept was foreign to me, and i've learnt alot, but you put up with my misunderstanding, and nudged me in the right direction. Just a few questions to finish off, and i should be out of your hair. I know the solution design now, i just have questions about parts :)

 

atxsas_jpg_fe3db86ffc5f900bd98177934c867

 

Made some notes on the img to ensure i understood what was going on.

 

Ok, so i wont be going the HP route. Upgrading my hardware, i don't want to go backwards with the expander. So what affordable SAS expanders should i look at, that wont have an issue with unRAID? Just had aquick look on eBay, looks like the only expanders in Aus are HP's!

Is the IBM 46M0997 ServeRAID Expansion Adapter 16-Port SAS Expander sufficient? IBM will ensure compatibility with my server...

 

From image:

What expander is in use in the photo? Is that molex power an addon or part of design?

Those PCI boards, what exactly are they called?

The SAS Expander is taking input from the HDD's, and also outputting - Are there designated ports on the card for input/output? Or is it a feature of an expander that it can detect inputs/outputs?

What's the role of the SuperMicro board, and can they be purchased individually? Name/model? It necessitates the need for a motherboard correct?

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25 minutes ago, Nasha said:

What expander is in use in the photo? Is that molex power an addon or part of design?

It's an Intel RES2SV240, it can be powered by molex or PCIe.

 

25 minutes ago, Nasha said:

Those PCI boards, what exactly are they called?

Do you mean the SFF-8088 to 8087 adapter? it's called that or SFF-8088 to 8087 bracket, like this:

image.png.7dc3d08f46089fcd5db51f26a010339d.png

 

External ports connect to the server, to an HBA with external ports or to another bracket, with cables like these:

image.png.86967723c7145df453bf2fba59808c9e.png

 

These cables are shielded and can be up to 10m long (including the internal cables from the HBA to the adapter and/or the adapter to the expander, if used) but you want to keep them as short as possible, I use 2 meter cables.

 

25 minutes ago, Nasha said:

The SAS Expander is taking input from the HDD's, and also outputting - Are there designated ports on the card for input/output? Or is it a feature of an expander that it can detect inputs/outputs?

All ports can act as imput/output, similar to a network switch, one or two ports are connected to an HBA, the remaining to the disks.

 

25 minutes ago, Nasha said:

What's the role of the SuperMicro board, and can they be purchased individually? Name/model? It necessitates the need for a motherboard correct?

It's optional, just so you can use the case buttons to power on/off, I bought it because found one very cheap, initially I just had a clip on the PSU to power on, p/n is CSE-PTJBOD-CB1

Edited by johnnie.black
  • Upvote 1
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13 minutes ago, johnnie.black said:

 It's an Intel RES2SV240, it can be powered by molex or PCIe.

 

Seems pricey compared to everything else, however it's also the only one i've seen with an independant power input which is a BIIG plus.

 

13 minutes ago, johnnie.black said:

Do you mean the SFF-8088 to 8087 adapter? it's called that or SFF-8088 to 8087 bracket, like this:

 

Thanks, assumed as much, but wanted to ask whilst i had the chance!

 

14 minutes ago, johnnie.black said:

External ports connect to the server, to an HBA with external ports or to another bracket, with cables like these:

 

8088-8088 cables, already sitting in my cart :)

 

14 minutes ago, johnnie.black said:

All ports can act as imput/output, similar to a network switch, one or two ports are connected to an HBA, the remaining to the disks.

 

Well there you go, most interesting piece of information i've learnt so far! That's nifty.

 

15 minutes ago, johnnie.black said:

It's optional, just so you can use the case buttons to power on/off, I bought it because found one very cheap, initially I just had a clip on the PSU to power on, p/n is CSE-PTJBOD-CB1

Ah ok - I might go without, no need to turn it off regularly enough to need a power button, and that way it's hidden from prying fingers. If i do find the need, i'll whip up a board of my own.

 

So i know exactly what i'm doing now, i just have the issue of sourcing a local SAS expander, and also the price of the Intel SAS (considering this was not budgeted for), i certainly want to avoid requiring a motherboard etc... So i need to prey i can find one 2nd hand in the forums, a bit cheaper, and local!

 

Thanks again for your time and expertise johnnie, greatly appreciated! I've wandered these forums long enough to know that you're one man who knows his sh*t, so i know i've got trusted information and probably the best available!

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