Slashdot Mirror
Open Compute Developing Wider Rack Standard
1sockchuck writes "Are you ready for wider servers? The Open Compute Project today shared details on Open Rack, a new standard for hyperscale data centers, which will feature 21-inch server slots, rather than the traditional 19 inches. "We are ditching the 19-inch rack standard," said Facebook's Frank Frankovsky, who said the wider design offered better heat removal and a unified approach to power, including a 12 volt busbar. The Open Compute Project, developed by Facebook to advance open source hardware design, believes an open approach can avoid the mistakes of blade server chassis design."
So put the server power supply on the outside, basically.
When the foot seeks the place of the head, the line is crossed. Know your place. Keep your place. Be a shoe.
The first mistake is that they are still talking in inches instead of metric units.
SURELY NOT!!!!!
These are better. They're 2 batter.
I don't see the point, to be honest. And aren't things supposed to get smaller as technology advances?
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
I detect a few years of market window for rails with 1" shims attached (19+2x 1" = 21) to allow old servers to wedge into the new racks.
There is a big distinction that you need to understand here, the Width of the Server chassis is changing, not the width of the rack itself. The outer dimension of the Server Rack is staying at 24 inches. The REAL problem was a bogus amount of extra cruft in the rack design that is going to be eliminated to make way for the wider servers.
There's already a standard for 23" racks widely used in telecom. So now we have to deal with 19, 21, and 23 options? Great.
Why invent yet another new standard when there's a perfectly good one already in use, with lots of inventory in place?
Telecom has used 23" racks for years. There are standard adapters already available to mount 19" hardware in a 23" rack. 23" racks are already available in the marketplace.
Further, why 12Vdc? Telecom has been using DC plant for decades and there is a ton of existing 48Vdc equipment on the market. There area existing cabling standards for all this as well.
Just seems like an attempt to fracture the market and create an opportunity to solve a problem that's already been solved.
> Open Compute Developing Wider Rack Standard
Well, programmers have been getting fatter over the years. I suppose this applies to the female ones, too.
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
As soneone responsible for machine infrastructure, this is a big deal.
21" racks means that I have to change the layout of my lab. Currently we have the mandatory 42" aisle (or whatever ADA requires) running the length of the lab, with banks of racks pedistileing (sp?) out from the wall with power and data. If all the racks were 2" wider I'd lose a rack in each row, so unless these machines improve density... it's a no sell for me.
whois gawk date unzip strip find touch finger mount join nice man top fsck grep eject more yes exit umount sleep dump
All will be forgiven if this standard is better than the current scheme. The *only* thing that's consistent about it is the width.
The current scheme has a lot of problems with rail-kits fitting into some racks and not others, because they're too deep, or not deep enough, or because one rack has small threaded holes on the inside of the posts, and another has the big square ones. In my set-up, we only have five racks, and already we're running into problems placing equipment because of differences in the mounting geometry.
Actually, I don't even really need standard mounts, I'd settle for consistent nomenclature -- then at least I could buy adapters, and finally be able to put any piece of equipment in any rack.
2*3*3*3*3*11*251
Why 12 volts? Telephone companies figured out decades ago that 48 volt positive ground systems were more desirable. They reduced the need for heavier copper wire, and they are not likely to be lethal shock hazards (though burns are certainly possible).
Furthermore, every motherboard has multiple switching supplies built in. We have 12 volts, 5 volts, 3.3 volts, 1.8 volts, and probably some adjustable voltages too. Some even have separate regulators for individual parts of the board. We will never be rid of the power supplies. We have simply moved them closer to the processors, memory, I/O, and GPU. Why not design the boards to use -48 volt battery systems as primary inputs so that we can reduce corrosion, use existing infrastructure designs, and keep I^2R losses down?
Nearly fifty percent of all graduates come from the bottom half of the class!
19 inch racks are the oldest standard in computing. The ENIAC used 19 inch racks.
This is really yet another "blade server" scheme. The whole rack is one chassis. Units are on vertically mounted boards with front faces and handles which look like an extra-deep variation on the old Eurocard form factor. That's reasonable enough. It's a lot like 1980s IBM mainframe or 5ESS packaging. Vertically mounted boards are better for airflow, anyway.
It's not about racks which take horizontal boxes like 19 inch rack components, but are slightly wider.
The spec can be downloaded from here
At first, I thought this sounded like a stupid idea too. Then, I read the spec. They're not just changing the width of the equipment area, and it's not just an extra 2".
External width is unchanged from the 19" rack standard, it's still nominally 23.6". No replacement of floor tiles or room redesign necessary.
Equipment width is increased from ~17" (on a 19" rack) to 21", it's allows 4" wider equip.
Power is handled in 3 "zones" per tower. Each power zone provides 12.5V DC power on each of 3 independent pairs of power rails, No AC power supply is required for each piece of equipment, but they will need DC-DC converters and VRs to supply the voltages needed for their specific components. That saves some space on each device, and provides a slight improvement in efficiency. Because this is standardized worldwide, there is no need for each device to have different power circuitry for different countries.
Because a zone can have triple power rails, devices can use 1, 2, or 3 power rails to provide whatever level of redundancy is appropriate.
Space for switches is included in each rack, along with power monitoring/reporting circuitry per rack.
Battery backup power can either be built into the power supply for each zone, or supplied from a separate battery rack.
The specification allows for many AC or DC power sources, this is the only significant part of the spec that will vary by country as the power units will need to support the available AC and/or DC supply.
All devices are to be hot-plug compatible.
So, it does have a lot of advantages.
Here are the concerns I have with it:
All power rails appear to be exposed. While they are on the back, this could be a significant safety (personnel and/or fire) issue. Considering that you can up to 500A @ 12.5V DC running through the zone power rails, and potentially more for the main cabinet DC power rails, exposed seems like a bad idea.
The standard allows depths from 36" to 48". With the way devices connect to power rails on the back, it looks like this means you will need to use devices designed for the specific depth of your rack, or use a shim to extend the device to match the depth of the rack. I believe they should standardize on one, or at most 3 depths, and have a standard set of shims to connect the devices designed for the shorter depths to fit the deeper racks.
make imaginary.friends COUNT=100 VISIBLE=false
That's covered in the article. 21" racks within the current 24" standard rack size. By eliminating cable mass in favor of bus-bars, you gain the two inches "free" in your rack footprint. If the rack's designed right, you could even keep the same seismic bracing.
Matthew P. Barnson
I learn what I think when I read what I write
Especially when they're STACKED!
Well, it's two wider, isn't it? It's not nineteen. You see, most blokes, you know, will be serving at nineteen. You're on nineteen here, all the way up, all the way up, all the way up, you're on nineteen on your rack. Where can you go from there? Where?