# ZFS Storage Pool on an EMC KTN-STL3 DAE



## DemoNIck (Jun 19, 2022)

I am thinking of upgrading my existing home FreeBSD ZFS storage pool server. 
The main idea is to use an external Disk Array Enclosure (DAE) with a SAS connection module connected to the main FreeBSD server through a PCI-e LSI HBA card. 
Unfortunately, I have zero experience on server equipment like the ones mentioned above. Although I have googled around a lot and I have red many blog articles, I feel like I might be missing something. So please allow me to ask for some additional information regarding a FreeBSD installation on such hardware.

The main FreeBSD server will be installed on a Supermicro Superserver 5018A-FTN4 with an Intel Atom C2758 CPU. 
For the external DAE I am thinking of an EMC KTN-STL3. That is a 15 Bay 3.5'' SAS HD enclosure with dual 6 Gb SAS controllers (Module : 2x 046-003-578_A03 / CM-1).
Because I will be using SATA HDs (and NOT SAS HDs), as far as I understand, I will have to use HD caddies with the appropriate  SAS/SATA Interposer. I am thinking of using the EMC 100-564-424 04 Tray Caddy SAS/SATA interposer. 
On the Supermicro FreeBSD server I will install a HP LSI SAS9207-8e 9200-8e 2x SFF-8088 6G SAS HBA Controller PCIe x8 and of course I will purchase the additional SFF-8088 cables. 

Does anyone have a similar installation (in my case using the EMC KTN-STL3 DAE) to verify that such hardware is working with FreeBSD? 
How do I have to connect the LSI HBA card with the EMC DAE?

Any comments, suggestions, corrections are welcome.

I would like to thank you in advance for your time.


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## ralphbsz (Jun 19, 2022)

In theory, this should work fine. The EMC enclosure looks like a fairly commonplace SAS enclosure, with two expander/controller modules in the back. The SAS HBA is a standard LSI/Broadcom card. I don't even know whether you need SAS/SATA interposers; some enclosures allow using SATA disks directly, but they will only be visible on one controller module (with interposers, they are visible on both). At this level, all of this is OS-independent, and if the setup works on Linux or Windows, it should work on FreeBSD.

You may want to use the sesutil to help manage the enclosure: Find out which disk is where, turn disks on and off if possible (I don't know whether this enclosure has power control per drive slot), control indicator lights.


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## Phishfry (Jun 19, 2022)

So why did you chose an external chassis for disks? That is my first question.
I would not worry about an external disk cabinet until you get above sixteen 3.5" drives.
Those adapter sleds seem like disk signaling nightmare and adds $150+ to your cost.
The weakest point (signaling errors) of hotswap bays is the connection point in my opinion.
You add one with an adapter (interposer).

I would avoid EMC and get something OEM. Like Chenbro or SuperMicro
What I worry about is side band signals.
You will find these build into many proprietary chassis and backplanes.
Special SF-8088/8043 cable with extra signaling wires.


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## Phishfry (Jun 19, 2022)

Also SAS92xx is really old now. Why not step it up a notch to =>SAS9300.
No sense buying obsolete cabling.


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## Phishfry (Jun 19, 2022)

Here is one word of advice. Research backplanes of anything you are looking at.
I have two SuperMicro 24 Bay machines.
One has 24 bays routed into two SFF8087 connectors. It has a controller on board.
The other backplane has six SFF8087 connectors. No controller.
So wiring of the backplane can be dramatically different.
It has an effect on pool drive distribution choices.


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## Phishfry (Jun 20, 2022)

DemoNIck said:


> Intel Atom C2758 CPU


This is ticking timebomb. Please avoid all C2xxx boards. I dunno if fixed silicon was every released.








						The Intel Atom C2000 Series Bug - Why it is so quiet
					

We take stock of the Intel Atom C2000 series bug and what vendors are doing about it. We are clearly seeing evidence of effective NDAs




					www.servethehome.com
				



Intel got away with this screw up unscathed.





						Intel Atom chips have been dying for at least 18 months – only now is truth coming to light
					

Vendors clocked C2xxx flaw when returns spiked




					www.theregister.com
				








						PSA: Intel's Atom C2000 chips are bricking products (inc. NASs, firewalls & servers)
					

If you have a device that contains a B0 stepping C2000-series Intel Atom processor from 2013 onwards (e.g. many Synology NASs inc. DS415+/DS1515+/DS181




					www.edugeek.net
				




Just don't reboot and everything is fine!!!!


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## Phishfry (Jun 20, 2022)

SuperMicro CSE-836 would be a good choice.
Around $300USD used.
There are all different CSE-836 models with different backplanes. Some only SAS1.
So knowing what you are looking at is important for a deal.

So how does that price square with the EMC gear? Is the EMC gear cheap for you?
I don't know your local used market.


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## Phishfry (Jun 20, 2022)

The nice thing about SuperMicro chassis is they are upgradable.
Lets say you get an older CSE-836 chassis with SAS1.
Jump on ebay and upgrade the backplane for cheap.








						Supermicro SAS836TQ Backplane With SAS to SATA Breakout Cables for sale online | eBay
					

Find many great new & used options and get the best deals for Supermicro SAS836TQ Backplane With SAS to SATA Breakout Cables at the best online prices at eBay! Free shipping for many products!



					www.ebay.com
				



The 836TQ backplane is made for SATA drives with 16 separate cables.
No controller onboard. Straight thru. You could use fanout cables to controller.(SATA to SFF8643)
Backplane upgrade requires deep teardown but it really is easy with only 3 screws.
I upgraded my 1U Supermicro backplane to SAS3 for low cost.
Blow the trash out of power supplies and good for many more years hopefully.

Here is the SAS1 version of the CSE836 backplane.








						Supermicro SAS836A 16 x 3.5" 3Gb/s SATA/SAS 3U Server Backplane  | eBay
					

Find many great new & used options and get the best deals for Supermicro SAS836A 16 x 3.5" 3Gb/s SATA/SAS 3U Server Backplane at the best online prices at eBay! Free shipping for many products!



					www.ebay.com
				




Here is the expander backplane version:








						SuperMicro BPN-SAS-836EL1 3U SAS/SATA Expander Backplane  672042025671 | eBay
					

Supermicro BPN-SAS-836EL1 3U SAS / SATA Expander Backplane with single LSI SASX28 Expander Chip.



					www.ebay.com
				




There is also a 836EL2 backplane that has dual expanders. Much better performance.

That is the state of matters on CSE-836 SAS1, SAS2 and SATA Chassis backplanes.
Then we have SAS3 Backplanes. SAS3-836EL1








						BPN-SAS3-836EL1 supermicro 16-port 3U SAS3 12Gbps single-expander backplane NEW!  | eBay
					

Find many great new & used options and get the best deals for BPN-SAS3-836EL1 supermicro 16-port 3U SAS3 12Gbps single-expander backplane NEW! at the best online prices at eBay! Free shipping for many products!



					www.ebay.com


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## DemoNIck (Jun 20, 2022)

Thank you all for your time and especially you Phishfry for your analytic answers.

I didn't know about the Intel's C2000 series bug! This is major! Thank you for sharing.

I finally ended up ordering a SuperMicro server - hosting now the FreeBSD OS and the zfs storage pools on the same "server".  I will also take under account the "newer" LSI 9300 series HBA controllers.

Regarding the prices, used "Server" equipment in european market (excluding the UK market) are general speaking higher, with fewer choices, than the US Market.


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