rack rails

1 - We now have some time on our hands to do some things in our storage area which includes identifying a # of rack rails found in a box. Does anyone have any tips or tricks for identifying what equipment rails might match?

2 - Do you know of any universal rail kits for 1U, 2U and 3U servers, routers, switches that work well? The brand names are nice but expensive. Thought I’d explore some cheaper options first. We use a lot of MikroTik, HP, Dell and some CISCO with a few other things here and there.

TIA

On point #1, I typically look for a part number and use Google. If a part number is present it often provide clues as to the brand, if not a range of compatible models. If no part number, sometimes the finish can provide clues - e.g. powder coated black rails or mounts often went with other items that have a similar coating (Belkin KVMs, some UPS units), while flat metal rails are common with other brands (Dell servers, Cisco routers/switches). I’ve taken to wrapping rails together in plastic wrap (the kind for wrapping pallets or moving boxes) and using a marker to label each set. Makes life easier down the road.

On point #2, I’ve found that using the brand name rail can save me hours of time. Either in easing the initial mounting or preventing problems down the road if a server needs to be pulled for maintenance or decommissioned. For anything that doesn’t have a rail, and I find the matching rails either prohibitively expensive or unavailable for purchase, a rack mount shelf can be used. Find one that works well with your racks to minimize the time required to mount/unmount. Good racks can make all the difference here. If you use a lot of Dell servers, Dell’s newer racks provide plenty of depth for their servers and the square holes are a perfect match for their square rails, making it possible to rack servers in a couple minutes. I’ve found Dell racks (or racks that work well with Dell servers) also work well with Cisco, APC, and servers from other vendors. I have not found the reverse to be true (e.g. racks made for network equipment often do not work well for many servers). In short, my time was more valuable than the money saved on struggling with mounting issues caused by bad rails or bad racks. Good racks and good rails save time.

–Blake

* David Funderburk

2 - Do you know of any universal rail kits for 1U, 2U and 3U servers, routers, switches that work well? The brand names are nice but expensive. Thought I'd explore some cheaper options first. We use a lot of MikroTik, HP, Dell and some CISCO with a few other things here and there.

When it comes to network equipment meant for mounting in four-post data centre racks with PSU-to-port airflow, the included kits are usually anything but nice.

The problem is that they typically only allow for insertion/removal through the rear of the rack (unlike servers, which are almost exclusively mounted through the front of the rack).

When a rack has been filled up, removal/insertion through the rear will often be essentially impossible due to cables, vertical PDUs and stuff like that that gets in the way.

Explained in pictures here: A rack switch removal ordeal – /techblog

If someone knows of a generic rack mount kit for data centre switches that allows for insertion/removal through the front of the rack, i.e. from/to the cold aisle, I'd be very grateful.

Best thing I've come up with so far is to use shelves, but that doubles the amount of rack units I need to use (1U switch sitting on top of a 1U shelf...)

Tore

I've been asking manufacturers for proper server-like slide-rails for their switches for years. Now they've started making the switches as deep or even deeper than servers, but they still use the same old rack ear mounting method.

I've had gear that came with a small rear support shelf that didn't had to the height, RGB Networks BNPs for example. I'm pretty sure we've used these with the BNPs one on top of the other.

Page 16 in this PDF shows the shelf.

http://www.konturm.ru/catalogy/df/bnp2xr_installation_guide_3.7.1_20160222.pdf

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    * David Funderburk
    
    > 2 - Do you know of any universal rail kits for 1U, 2U and 3U servers, routers, switches that work well? The brand names are nice but expensive. Thought I'd explore some cheaper options first. We use a lot of MikroTik, HP, Dell and some CISCO with a few other things here and there.
    
    When it comes to network equipment meant for mounting in four-post data centre racks with PSU-to-port airflow, the included kits are usually anything but nice.
    
    The problem is that they typically only allow for insertion/removal through the rear of the rack (unlike servers, which are almost exclusively mounted through the front of the rack).
    
    When a rack has been filled up, removal/insertion through the rear will often be essentially impossible due to cables, vertical PDUs and stuff like that that gets in the way.
    
    Explained in pictures here: https://www.redpill-linpro.com/techblog/2019/08/06/rack-switch-removal.html
    
    If someone knows of a generic rack mount kit for data centre switches that allows for insertion/removal through the front of the rack, i.e. from/to the cold aisle, I'd be very grateful.
    
    Best thing I've come up with so far is to use shelves, but that doubles the amount of rack units I need to use (1U switch sitting on top of a 1U shelf...)
    
    Tore

Once upon a time, Chuck Anderson <cra@WPI.EDU> said:

I've been asking manufacturers for proper server-like slide-rails for their switches for years. Now they've started making the switches as deep or even deeper than servers, but they still use the same old rack ear mounting method.

Maybe it's because they're primarily a server vendor, but Dell switches
(at least the N3000 series I've used most recently) have 4-post mount
rails. IIRC they aren't extending sliding rails like the servers have,
but the switch slides into the rails.

* Luke Guillory

I've had gear that came with a small rear support shelf that didn't had to the height, RGB Networks BNPs for example. I'm pretty sure we've used these with the BNPs one on top of the other.

Page 16 in this PDF shows the shelf.

http://www.konturm.ru/catalogy/df/bnp2xr_installation_guide_3.7.1_20160222.pdf

Interesting, thanks! Such a shelf would do the trick if it is thin enough to fit in the tiny space between two devices mounted in adjacent rack units.

Do you know if it is possible to buy this kind of shelf from somewhere (without an accompanying device)?

Tore

The point is that the switches need to be removable without empty
space above/below, and ideally from the rear side of the rack. By
having extending/sliding rails, you can lift out or drop in the switch
after you slide it out. Then you can remove the rails.

With fixed rails, you can't get the switch out without bending the ear
part of the rails when there are PDUs and other stuff in the way.

Juniper's ToR switches have slide in rails. They are a bit frustrating compared to Dell easy rails, but they do the trick.

I've been asking manufacturers for proper server-like slide-rails for their switches for years. Now they've started making the switches as deep or even deeper than servers, but they still use the same old rack ear mounting method.

The Arista 4 post rack kits are pretty good. Toolless as well.

       - Ethan O'Toole

* Chuck Anderson

The point is that the switches need to be removable without empty
space above/below, and ideally from the rear side of the rack. By
having extending/sliding rails, you can lift out or drop in the switch
after you slide it out. Then you can remove the rails.

With fixed rails, you can't get the switch out without bending the ear
part of the rails when there are PDUs and other stuff in the way.

Not necessarily. Even sliding rails must be constructed in a way that facilitates removal through the cold aisle side of the rack. That's not a given.

One example of sliding rails that unfortunately do *not* allow for removal that way is the Edge-Core RKIT-100G-SLIDE:

A look at our new routers – /techblog (Ctrl+F Bonus)

Tore

You can slide the switch in/out while attached securely to the rails? That is news to me and my QFX5k and QFX10k switches.

Now that you say that, I think you're right. I am referring specifically to the EX4650 and they are the cheesy type where the rear half of the rail stays screwed in to the rack and the front half of the rail is attached to the switch. I assume it is the same on the QFX since they are very similar platforms. Basically they are that annoying type between rack ears and sliding rails where the device can separate completely from the rails.

chris

I'd be happy with removal from the hot aisle, because I've already had to do that many times and if you manage cable routing properly it isn't as much of an issue. Granted, getting everyone to be neat with their cable routing is not easy, but at least cables can be moved around. The biggest issue for me is how the ears remain attached to the equipment while you insert or remove it. If the ears/rails could be mounted to the empty rack U first and the switch slid in second (and the reverse for removal), that would be fine for me. As it is now, there is basically no way to deal with the ears other than bending/destroying them on the way out. And that doesn't solve the case for installing new switches in a dense rack.

* Cummings, Chris

Now that you say that, I think you're right. I am referring specifically to the EX4650 and they are the cheesy type where the rear half of the rail stays screwed in to the rack and the front half of the rail is attached to the switch. I assume it is the same on the QFX since they are very similar platforms. Basically they are that annoying type between rack ears and sliding rails where the device can separate completely from the rails.

Looking at the documentation (linked below), it would appear the EX4650 has the exact same rack-mount kit as the EX4500 and EX4600 do.

They all share the fundamental problem I'm taking about, namely that there are fixed mounting ears on the port side of the switch, which prevent removal through the cold aisle (assuming data centre/PSU-to-port airflow).

The "sliders" are really just there to prevent the PSU end of the switch to sag.

Tore

https://www.juniper.net/documentation/en_US/release-independent/junos/information-products/topic-collections/hardware/ex-series/ex4650/quick-start-ex4650.pdf (page 6)

We tried to flip the sides of rails in QFX5120 and it cause two problems that prevent us from keeping it this way

  1. The switch was 2 cm from the rear post line
  2. The switch vibrate as you can see in the video
    https://photos.app.goo.gl/WQwcE9vcPjSiEi9N9

Nitzan

That is unfortunate, but amusing.

Not sure to be honest, I see the following though which may work just not sure how thin this one is. I noticed in the DOCs it says not to use if placing directly on top of another device, which you could assume might mean it's too thick.

BTI7801 Chassis Support Bracket Kit (BT8A78SSB3)

https://www.juniper.net/documentation/en_US/release-independent/bti-series/bti7800/topics/concept/concept-c-hwoig-7800-rack-mounting.html

    *External Email: Use Caution*
    
    * Luke Guillory
    
    > I've had gear that came with a small rear support shelf that didn't had to the height, RGB Networks BNPs for example. I'm pretty sure we've used these with the BNPs one on top of the other.
    >
    > Page 16 in this PDF shows the shelf.
    >
    > http://www.konturm.ru/catalogy/df/bnp2xr_installation_guide_3.7.1_20160222.pdf
    
    Interesting, thanks! Such a shelf would do the trick if it is thin enough to fit in the tiny space between two devices mounted in adjacent rack units.
    
    Do you know if it is possible to buy this kind of shelf from somewhere (without an accompanying device)?
    
    Tore

I have considered making my own rails using a laser cutting service. I have done this before where I created 500 mm to 19 inch rack adapters and had them laser cut at lasergist.com. Fairly simple really, just make a drawing in Fusion360 and upload the drawing. A few days later the adapters arrived.

Rails would probably require some metal bending but could otherwise be made the same way. Maybe we could do an open source design here?

Regards

Baldur

Hi,

something like https://www.opencompute.org/projects/rack-and-power
comes into my mind for that.
Mounting on 4 posts should be the default. It is insane what some
vendors want to mount on 2 posts only.

Regards, Karsten