Supermicro Rail Failure?

Discussion in 'Chassis and Enclosures' started by Eru0194, Jun 27, 2019.

  1. Eru0194

    Eru0194 New Member

    Joined:
    Jun 13, 2019
    Messages:
    10
    Likes Received:
    2
    I recently purchased an SC846B chassis and I'm trying to find out which rails are the best for this. It seems the best options are:
    This is the clearest comparison I could find. The biggest difference seems to be that MCP-290-00053-0N (yellow label) rails extend far enough to remove the lid of the chassis while it's racked. This is obviously ideal, but I'm not sure how safe it is.

    The problem is that Supermicro can't/won't approve the MCP-290-00053-0N rails for their 4U chassis. I know many people are using them anyway, and I'm wondering if anyone has seen these rails fail when they're used with a fully-loaded 4U chassis. I haven't been able to find maximum load specs for any of these rails.

    I've read every post I could find about SC846 rails. I'm hoping some people that have been using their 4U chassis with MCP-290-00053-0N (yellow label) rails for a long time might share their experience here.

    I'm not worried about my rack tipping, just the possibility of rails failing while fully extended. Has anyone seen or heard of this happening?
     
    #1
  2. j_h_o

    j_h_o Active Member

    Joined:
    Apr 21, 2015
    Messages:
    379
    Likes Received:
    76
    FWIW, I have an SC846 that is fully loaded with drives, and have not had an issue with the rails failing. It's been in this configuration for probably 6+ years, and I've worked on this server over 30 times, leaving the server open (while working on it) each time.
     
    #2
    Eru0194 likes this.
  3. Eru0194

    Eru0194 New Member

    Joined:
    Jun 13, 2019
    Messages:
    10
    Likes Received:
    2
    Thank you. To be clear, are you using the yellow label rails that fully extend?
     
    #3
  4. j_h_o

    j_h_o Active Member

    Joined:
    Apr 21, 2015
    Messages:
    379
    Likes Received:
    76
    I know for a fact that I'm using MCP-290-00053-0N and I believe they're yellow as you described.
     
    #4
    Eru0194 likes this.
  5. BLinux

    BLinux cat lover server enthusiast

    Joined:
    Jul 7, 2016
    Messages:
    2,370
    Likes Received:
    838
    This is how I think about it... between the 2 full depth rack options (MCP-290-00053-0N, MCP-290-00057-0N):

    If you use the "blue" label, the rails are effectively useless (without workarounds) because if the purpose of sliding out your server is to open it, you can't. So, what happens then? You have 2 workarounds:

    1) you unlatch the lock, and slide it 3-4 inches further out just on the inner rail to be able to open the lid. this seems more dangerous than using the "yellow" label in my opinion. For one, you're extending it with only the inner rail, instead of in combination with the middle rail. And secondly, the rail is unlatched so it could slide all the way off. This all seems less safe.

    2) you leave the 1U space above the server vacant, so you can reach into the space to open the lid. this seems the safer option, but wastes the 1U space and you can't block it off.

    OR.. just use the "yellow" label rails.
     
    #5
    nikalai likes this.
  6. Fritz

    Fritz Well-Known Member

    Joined:
    Apr 6, 2015
    Messages:
    1,899
    Likes Received:
    392
    My 2 cents worth -

    I have 4 SC486 chassis's fully loaded and using the yellow label rails. I fully extend them all the time and have never had a rail failure.
    However, I have had the inner rails come off the tracks on others chassis/rails and realize that if this were to happen on a fully loaded SC 846 it would coming crashing to the floor. I therefor err on the side of caution and place a lift table under the chassis when I fully extend it. It's not always high enough but it greatly reduces the distance a chassis would fall if the rails failed. :)
     
    #6
    BLinux likes this.
  7. BLinux

    BLinux cat lover server enthusiast

    Joined:
    Jul 7, 2016
    Messages:
    2,370
    Likes Received:
    838
    I have 846 servers fully loaded with the yellow label rails and have never had a problem either. But, I really like your idea of putting a cart or table underneath it! That's a really nice suggestion, at least the server won't be falling on your toes.

    BTW, regarding the "inner rails" coming off the tracks, I've seen that with mismatched rails between so-called "Rev A" (not labeled as such) and Rev B rails. Is that what happened? or was it a properly matched rail set that came apart?
     
    #7
    Fritz likes this.
  8. Fritz

    Fritz Well-Known Member

    Joined:
    Apr 6, 2015
    Messages:
    1,899
    Likes Received:
    392
    Not sure if they were mismatched or not but it is a possibility. Next time I have the server in question out I'll check. Thanks.
     
    #8
  9. ecosse

    ecosse Active Member

    Joined:
    Jul 2, 2013
    Messages:
    361
    Likes Received:
    60
    Server rails generally are the invention of the devil. Never has so little cost so much and yet been the source of so much frustration.

    Having said the, the Supermicro and HP rails I've had have generally been solid.
     
    #9
  10. n17ikh

    n17ikh New Member

    Joined:
    Jul 12, 2019
    Messages:
    5
    Likes Received:
    1
    So I have actually had a Supermicro rail fail catastrophically. It was an SC836 chassis fully loaded with drives with MCP-290-00053-0N "yellow label" rails from ebay. I extended the server to do some work and one of the rails had the inner rail and slider separate from the outer rail, dropping the server and spraying tiny ball bearings all over the place. I was able to catch it with my knees and save it from hitting the ground but it was pretty hairy for a bit, especially since all the cables on the rear were still plugged in and not long enough to deal with sitting the server on the ground!

    I don't fully trust the Supermicro rails; they seem cheap and prone to that kind of failure mode. Before I had Supermicro equipment I had some older Poweredge servers (PE2950) and the Dell rapid rails for those were built a lot more solidly.

    I'll have to check when I get home whether the inner and outer rails were mismatched in revision, I didn't realize those had a rev A/B. That particular chassis had the inner rails when I got it and the outer rails were purchased separately.
     
    #10
  11. BLinux

    BLinux cat lover server enthusiast

    Joined:
    Jul 7, 2016
    Messages:
    2,370
    Likes Received:
    838
    glad there were no injuries from that incident!

    the differences in "rev A" (which is the non-labeled version) vs "rev B" are described in this video:



    in case that helps identify the combination of rails you have. please let us know if it was mismatched or if it was properly matched and still failed.
     
    #11
  12. nikalai

    nikalai New Member

    Joined:
    Oct 26, 2018
    Messages:
    21
    Likes Received:
    4
    I searched recently for two sets of rails for two Supermicro 846 servers. In Europe are hard to find and too expensive. So i ordered MCP-290-00014-00, those are the "old style" but also much cheaper. I searched recently for two sets of rails for two Supermicro 846 servers. In Europe are hard to find and too expensive. So i ordered MCP-290-00014-00, those are the "old style" but also much cheaper.

    chp.JPG

    The package is in transit.
     
    #12
  13. JSchuricht

    JSchuricht Active Member

    Joined:
    Apr 4, 2011
    Messages:
    154
    Likes Received:
    48
    Be careful with those old style rails. The rollers in front fail and let the server fall. My first SC846 came with those when I bought it in 2009. I have to keep it mounted at a height I can support with my knees as both sides have failed.
     
    #13
    nikalai likes this.
  14. n17ikh

    n17ikh New Member

    Joined:
    Jul 12, 2019
    Messages:
    5
    Likes Received:
    1
    Looks like both inner and outer rails are rev A on the failed set. Could be that's part of why they had a new revision.
     
    #14
    Eru0194 likes this.
  15. BLinux

    BLinux cat lover server enthusiast

    Joined:
    Jul 7, 2016
    Messages:
    2,370
    Likes Received:
    838
    thanks for checking! that's very interesting indeed...
     
    #15
Similar Threads: Supermicro Rail
Forum Title Date
Chassis and Enclosures Supermicro SC836 / Compellent CT-SC030 Rail Kit Dec 29, 2018
Chassis and Enclosures Do "Fixed" or "Non-Sliding" Rails Exist for Racking a Supermicro 826 Aug 18, 2018
Chassis and Enclosures how to tell the difference between "rev A" vs "rev B" supermicro rack rails? Apr 9, 2018
Chassis and Enclosures Do Supermicro SC846 and SC847 share rail mounts and parts? Nov 4, 2017
Chassis and Enclosures Supermicro 846 chassis fully extended rails question Sep 20, 2017

Share This Page