Converting a NetApp DS4243 drive shelf into a vendor-generic JBOD array

NetApp makes some nice hardware that you can occasionally find for a low price on eBay.  Unfortunately, it is typically hard to reuse since NetApp tends to require specific firmware on the hard drives in their drive shelves.  So you are then locked into their harder to find and higher-priced drives.

With a bit of experimenting, I found a method to get around this for at least one family of hardware.

Netapp’s DS4243 is a 24-bay SAS 6Gbps drive shelf.  It typically is configured with a pair of supplies (can support up to 4) and two IOM3 modules (which only support 3Gbps, but other versions exist).  I managed to pick one of these up off eBay for just under $100 with the pair of supplies and IOM3 modules mentioned.

Note I didn’t even try to use the IOM3 modules.  There might be other ways around the limitations I read about online, but I found a simple and inexpensive option that allows the disk shelf to be used as a generic JBOD array.

I also had a Dell Compellent HB-1235 12-bay SAS  6Gbps drive shelf.  This drive shelf comes with a pair of much longer named controllers (HB-SBB2-E601-COMP) that already present the drive shelf as a JBOD array to FreeNAS.  It turns out, these were manufactured by a company called Xyratex, who just happens to also manufacture the Netapp DS4243.

So what would the chance be that a Dell controller would work in the Netapp drive shelf?

I did some research, and the form and fit of the controllers matched perfectly.  The connectors are identical and placed in the same locations.

Front of the modules.
Rear of the modules, showing identical connector types and placement.

Now there is a chance that the pinout could have changed, power rails could be different, or some other issue might exist due to the fact that these weren’t specified to be connected together, but I was willing to take that chance for the sake of research.  Designing hardware in a similar industry, I took a bet that they were at least close enough to do something without blowing up.  That only question for me was how well would it work.

So all there was left to do was to plug it in and power it up!

Status is green and SAS link lights all good to go!
Drives powered up and show activity.
The NetApp drive shelf even identifies properly!

I was curious if possibly the HB-1235 controller would only see half of the NetApp drive shelf, since it was specifically used in a 12-bay drive shelf.  I purposely inserted a 500GB drive in bay 24 to test if it would work, and it identified properly with no issues at all.

So they identified, but would there be any stability issues?  To at least get a first-order estimate of this, I copied roughly 250GB of data to the array of 6x 3TB drives and had no issues. This was done over a 1Gb link.  After the copy was complete, a scrub of the volume was also successful.

The HB-1235 with two modules and two supplies cost me $120, and the NetApp was around $80.  Each unit only needs one module to run (though the HB-1235 seems to want to run the power supply fans on high when only one module is inserted).  A separate modules runs about $50, so you on a good day on eBay you can have a full 24-bay generic disk shelf for less than $200.

7 thoughts on “Converting a NetApp DS4243 drive shelf into a vendor-generic JBOD array”

    1. Noise levels are pretty minimal given it’s rackmount hardware. It’s not silent by any means, and the two large fans on the power supplies run at a low RPM (at 25-30C) ambient. There is no high-pitch whining what you get from 1U enclosures/fans. I don’t think I would hear it in a closet with a closed door. I’ll get actual test numbers for power and noise once I get back from Thanksgiving holiday.

  1. Thanks for the info, I was going to get a DS4243 anyway so I decided to go this route with the Dell controller.

    Have the same setup but its not working for me. The HB-SBB2-E601-COMP flashes its green lights 4 times when I power the disk shelf on but then goes dark (no green check or connection lights or even orange warning). The front orange ! warning light on the DS4243 is on and I notice yours is not in the picture.

    Tried swapping the IOM3 to the top and Dell on bottom. Drive lights come on this way, but still orange ! warning and no lights on dell controller and no connection. Tried using the other IOM3 I have. Also tried two different 8088 cables.

    Tested with just the two IOM3s and the orange ! still comes on at the front, no warning light on either IOM3s in the back… Seems odd. 🙁 I dont have a SFF8088->QSFP cable to try connecting to a IOM3.

    Right now I dont know if the backplane of my DS4243 is bad, the Dell controller is bad, or something just needs programming with a serial port. Any help would be huge! I’ll keep you updated if I get it figured out.

    1. Seems like your chassis might be bad. Best bet is to use the IOM3 console port to try to determine the issue. I haven’t actually used the IOM3’s so you will have to research the systems manual online.

      I wouldn’t insert both the IOM3 and HB controllers at the same time as they are totally different systems that probably try to master the chassis in their own way and probably don’t talk to each other properly, so if that’s what you are doing then only insert one type of controller or the other. I put the IOM3 in the second slot but didn’t insert it fully just to use as a placeholder to ensure proper airflow through the system. I’d hope that inserting both types at the same time wouldn’t cause damage, but that is also a possibility.

      1. Oh I thought you had both installed! I seen the picture (now I can tell its not fully inserted), plus you said how the fans run on full with just the HB so I figured that you hadn’t left it that way.

        I did get the 2xIOM3 to startup without the orange ! light, think I had a extra PSU installed but not plugged in last time. So I think those may be working. I have a 8088->QSFP on the way I will see if that works. If so I’ll probably just use that because I dont want the fans on full. If not I’ll try to get a refund on the shelf.

        I tried to find terminal info but couldn’t find much. If you search for SBX_UserGuide_2.7.pdf it has info on the HB controller and the disk shelf warning lights. Said power+! at the front can be: Power fault or Module fault, or enclosure fault so not too useful.

        But no terminal commands or anything, just says the 3.5mm serial jack is for factory use only on the SB controller.

        Have you tested installing two HB controllers do the fans still run on full? Would be nice to know.

  2. On the Dell chassis the fans would run on full with only one HB controller and normally with two, but on the Netapp chassis the fans seem to run normally even with only one HB controller.

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