EMC KTN-STL3 15 bay chassis

Andrew V

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Jan 28, 2019
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Hi,

sorry for 10 day old reply - but I thought i'd chime in.
I have one of these, connected to a Dell H200 (flashed)

Uses SAS/SATA drives interchangeably if you use the bottom controller. Make sure the chassis includes interposers, as they have multiple model numbers which can cause some issues. Reportedly, top controller only supports SAS, but i've never tested.

If it comes with EMC drives, they'll be 520 byte, and you need to use sg3_tools to format to 512 byte format. (On a 2TB drive, this takes about 10-12hours!)

If you have any questions, let me know :)
 

BeTeP

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Mar 23, 2019
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My goal is to find an inexpensive (under $10/bay shipped) preferably short and not very loud 6Gbps SAS/SATA enclosure which is readily available in the US. I decided to try the EMC KTN-STL3. So I have bought a couple of STL3 and STL4 units to play with. I paid about $60 shipped for a STL3 (2x PSU + 2x 6Gbps SAS controllers, no drives/trays included) and about $40 for a STL4 (2x PSU + 2x 4Gbps FC controllers, no drives/trays). Then I ordered some disk trays and some extra interposers at about $9 per tray with interposer and about $5 per interposer alone. There were some better deals for bulk orders but I was not yet sure which models would work so I just ordered those for now.
To meet my $10/bay goal I would need to find 15 trays with proper interposers for under $90 shipped. I think it is possible. From my previous experience buying enclosure with trays already included is usually less expensive than trying to buy them separately. But there was literally no auctions listed for enclosure + trays for a few weeks I have been looking. There were a few auctions for the enclosure + disks but I was not interested in 300Gb 15K.

The official documentation is very confusing and I did not find any explanation of the difference between the 2 models. But from looking at what's listed on ebay it seems that STL3 is available with both SAS and FC controllers while STL4 only comes with FC. So naturally the very first thing I tried to do was to swap the controllers between the units. And it (i.e. STL4 combined with SAS controller) seemed to work just fine.

After I get enough trays to fill one enclosure completely I am going to run more tests. Specially power draw and noise level related.
If you have any other ideas of things to test - let me know.
 
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BeTeP

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Mar 23, 2019
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My orders keep coming. After couple of hours I was able to find plenty of trays with interposers at about $5 shipped. Since the description was very vague it remains a mystery whether the trays would come with proper interposers or I would have to buy different ones later on. But that should not be that big of a problem. Many sellers seem to be happy to accept much lower price for the bulk orders of interposers than they asked for originally.

In the meantime I am still trying to figure out the difference between the STL3 and STL4. And besides the style of the front bezel and original trays I could not find anything else. The power supplies are exactly the same. The backplanes are the same. At least in all 6 of my units.

Counterintuitively, the STL4 is the older model. It makes it cheaper but since it is not available with SAS controllers - you'll have to buy those separately and it would eat all the potential savings. So just get the STL3 with SAS controllers included if you can.

The trays as I already mentioned are slightly different styles but interchangeable. The older ones are made of some alloy and the newer ones are made of ABS plastic. Again - get the new ones if only to save on the shipping costs.

The most surprising to me part was the backplane. Despite having FC connectors, I do not think the board has any FC specific circuitry. Just general buffers and power distribution stuff. Which finally brings us to the most important stuff - the interposers.

The FC interposers have an Emulex SAS-to-FC converter chip which enables the SAS drive in the tray to talk to the FC controller in the chassis.
The SATA/SAS interposers have... nothing! Well just power and tray LED control related stuff. So the SAS/SATA drives talk directly to the SAS expander on the SAS controller in the chassis.

So the proper interposers are very easy to spot - no Emulex chip = good, has the Emulex chip = bad.
 
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Dave Corder

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Dec 21, 2015
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Not that I need more disk shelves, but I'm curious about the noise levels of these units. Subscribed to the thread for updates...
 

BeTeP

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Mar 23, 2019
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I connected the shelves via Kill-A-Watt today.

An empty shelf sits at around 35-40W.
The shelf filled with 2.5" 10K SAS drives idles at around 100W.
The shelf filled with 3.5" 7.2K SAS drives idles at around 160W.

As for the noise level - I did not take any measurements yet as that would have required me to find an empty(quiet) room in my basement. But empirically I'd say these are noticeably less loud than any of my 2U servers and other 2U storage enclosures.
I would not sleep next to it but the noise did not bother me when I was working on it.

In other news, EMC Unity Hybrid series still uses the same chassis for its 15x 3.5" 3U DAE with 12Gbps SAS controllers (EMC P/N D3123F). The 10+ years old FC (originally 2Gbps) enclosure can be upgraded to 12Gbps!
 
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BeTeP

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Mar 23, 2019
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are these selfs limited to 2tb disks? or beyond 2tb is also soppurted?
These shelves work just fine with bigger drives. 2Tb is my throw away set just for testing.

Also to my knowledge the 2Tb limit was never an issue with enclosures (i.e. SAS expanders) just HBAs.
 

BeTeP

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Mar 23, 2019
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The next issue is mounting the enclosures in my rack cabinet. The lowest price for the set of EMC rails I found so far is $40 shipped. And they are too short for my rack. I am thinking about getting a generic 6U shelf for every 2 enclosures instead.
 

Subpacket

New Member
Aug 9, 2013
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London, ON, CA
KTN-STL3 - how can you tell if its got a FC or a SAS controller, or they have both in it and its why you connect to the circle port and not the triangle port. What interposers work with this unit for sas/sata drives, or just pick up sleds that have the sas/sata drive already in them. It looks like sleds are about $10, and a cheap drive already in the sled is about $20?
 

Andrew V

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Jan 28, 2019
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by default/assumption: ebay listings of
KTN-STL3 is SAS
KTN-STL4 is FC

interposers are a little hit/miss, which is why the recommendation is to purchase them with the chassis.
 

Subpacket

New Member
Aug 9, 2013
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London, ON, CA
Ok, so the controller has bother fc and sas. Getting a SAS interposer allows your drive to talk to the sas controller, which is what we want.

Plug into the sas controller (circle) and use sas interposers (that don't have a chip).
 
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BeTeP

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Mar 23, 2019
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None of the controllers have both interfaces. It's either one or another. Each enclosure needs 2 identical controllers to work properly (without alarms and screaming fans).
 

SINN78

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Apr 3, 2016
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The next issue is mounting the enclosures in my rack cabinet. The lowest price for the set of EMC rails I found so far is $40 shipped. And they are too short for my rack. I am thinking about getting a generic 6U shelf for every 2 enclosures instead.
Did you ever find cheap rails for these?
 

BeTeP

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Mar 23, 2019
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As I said the original EMC rail kit for this shelf is fixed length and shorter than most of server racks. So I am just using generic L-bracket type of rails for these.
 
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Subpacket

New Member
Aug 9, 2013
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London, ON, CA
Im up to 6 of these enclosures, with 5 rail kits. They have been hit or miss, averaging about $20US. 2 in canada, 3 in the US. Just keep an ebay search going for them, never the same vendor.
 
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