Quieting down my server rack

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Quieting down my server rack

Post by furious » Sun Aug 17, 2008 4:38 pm

I have just set up my own business and am doing everything on a budget. :) As a result my office is very small and the way it is laid out, I am sitting right next to my server rack.

Reliablity is more important than noise, but the noise of all the componets is approaching that of a small aircraft! It's dificult to talk on the phone and people always make comment on it.

I am not really interested in reducing number of fans as I don't want to jeadodise the reliablity in any way. And moving desks and / or server rack is not an option.

I am thinking of possibly putting some sound absobing foam on the inside of the cabinet, but am not really sure if it will do much.

Below is a photo - any advice would be greatly appreciated!


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Post by didi » Mon Aug 18, 2008 2:47 am

Those fans on top, are they 120mm ? At full speed ? Maybe 4 is overkill, try removing 2. Reliability/redundancy is ok with 2.
Sound absorbing foam on the inside will probably be the best thing to do (apart from silencing the machines IN the rack) because you have large surfaces.
Servers were never designed to be silent in the past, but nowadays most also come with temperature-regulated fans. Maybe time for an upgrade ;)

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Post by furious » Mon Aug 18, 2008 1:37 pm

Yes, the fans are 120mm and yes they are full speed. They are 240volt.

I'll unplug 2 of them and monitor the temp inside to make sure it's ok.

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Post by TheAtomicKid » Thu Aug 21, 2008 2:42 am

Don't block or close it in, or anything, but... you could try putting some sound absorbent materal on/around the server area, so as to limit reflective surfaces, etc, and dampen the sound.

Rather than sticking say, old shag carpet directly to the walls, you could build yourself a set of plywood panels/structure, 3 or 4 sides, and glue it to that, then set it in place around the server. Thus, when you move the office, it's easy to move your sound dampening enclosure as well.

Remember not to block the airflow or your rack will get toasty. :)

It looks like the rack comes to just at the height of what appears to be cubicle partitioning or something next to it. If you make your plywood structure three sided, and extend it upwards (or even put a top on it), it should significantly reduce the effective noise... again, account for where the air must go...

note: a LOT of the sound, will be coming out the back of the unit, hitting the wall behind, and reflecting out into the room. Even just one board leaned up against the wall behind the rack, with appropriate material on it, should help... and it'd be cheap enough to test out the effectiveness. Then, you could decide whether to do more along that line, or adopt some other strategy.


PS: If you're short on carpet samples to try out, head down to the local carpet/tile/etc store and ask if they have any scrap pieces you can buy on the cheap (sometimes they might give them to you)

16 fans in the server? good lord. The four blowhole fans up top look promising for evacuating hot air though. You might be able to enclose if fairly well, if you take those into accound, and seal the external airflow properly... force it to suck from the bottom, and blow out the top, so that the air doesnt recycle, etc.

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Post by Magic » Thu Aug 21, 2008 3:04 am

I know racks are cool and all---

But I can't help but think you'd be better off just getting a regular case and rebuilding your server in that. Especially if it uses a standard ATX motherboard.

How many harddrives are in the server? In the harddrive stack?

Why do you need a switch with two fans for one computer?

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Post by matt_garman » Thu Aug 21, 2008 4:50 am

Is the back of your rack open or closed? I have a rack that came with a back door, but my equipment is too deep, so I just took it off. So all the hot air from my equipment blows out the back and doesn't get trapped inside the rack enclosure. So while there are cutouts for rack fans if I wanted to use them, I don't see the point. In other words, if the back of your rack is open, I doubt you even need those rack fans. And if the back of your rack isn't open, open it up and disable those top fans.

Can we get the specs on your hard drive stack and server?

Also, are you running any thermal monitoring on your hardware? Generally, cooler is better, but if you're using all those fans to keep the hardware at ambient (room) temperature, that's overkill.

Another approach is to figure out what is making the most noise in your server rack. It's the same concept we use in individual PCs: usually, there is one component that is the loudest or most obnoxious. What you do is go through each noise-making device (usually fans) and disable them one at a time. You might want to start with groups of noise-makers in the interest of time. For example, turn of all those top rack-fans---how much is noise reduced? Turn of the hard drive stack---does it make a noticeable difference? Turn off the server---how's it sound?

The idea is to find the "low hanging fruit", and work on quieting the loudest devices first.

Another take on those top four fans: if you have the equipment, cut a giant hole in the top of the rack and replace the four fans with one much bigger fan. The idea being that you can get a bigger fan that runs slower, and is thus quieter (without sacrificing airflow).

You said you're on a tight budget, so spending big bucks probably won't be your thing, but... I recently found I needed a bigger switch, so I ordered the HP J9078A 1400-24G. It's rackmountable and fanless. (I'm currently using its little brother, the 8-port version of the same line.)

If you decide to upgrade your equipment, take a look at my rackmount file server. It's not silent, at least by SPCR standards, but for a system with eight drives, it's pretty quiet. I monitor temperatures very closely, and I'm not concerned about any heat-related reliability issues.

I also like the ideas others have mentioned that involve building a three-sided enclosure for the rack. You could build and intake vent at the bottom front of your self-made enclosure, and even get fancy and have some ducting vent the hot air up to the ceiling or even into another room. If you can vent into another room, then you can have attach a high-power "suck" fan to the duct, and really move a lot of air through the enclosure, without too much noise (in your office anyway).

Good luck. Keep us posted on your progress!


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Post by furious » Thu Aug 21, 2008 3:56 pm

To give you an idea where it sits in the room see the below picture.

The rack usually is 4 degrees warmer than the room (room: 23deg, rack: 27deg)

I tried turning the 4 fans off in the roof of the rack, but the temp went up to 34 and whilst it helped a bit with noise, it didn't make heaps of difference.

The fans in the hard drive stack and switch are fixed and can't be disabled with out getting in a messing around with them (they are only small and quiet anyway).

Server has 4 hard disks. Hard drive stack has 6 hard disks.

I have the back of the rack closed in.

Without a doubt, the main source of noise is from the server - it has 16 fans. 6 of those are in the power supplys and i'm not touching those. The other 10 are in the server it's self.

It has :
2 fans at the front of the case.
1 Fan for each CPU (4)
2 Fans at the back of the case
2 fans to pull air over the hard disks and pci cards.

Each fan sits in a cradle that links back to the motherboard to report if it is working or not, so rubber mounting them is difficult.

Anyway, I am first going to line the inside of the rack with carpet or foam (3 sides and floor) and see what happens.

Thanks everyone for their advice! :) Will keep the thread updated with things I try and results.


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Post by furious » Sun Sep 21, 2008 3:00 pm


I bought some 38mm acoustic foam and lined the inside of the back door, the two removable side panels and also the roof.

It has made a significant difference, and whilst I don't have a db meter, I would say it has cut the noise from 1/3 to 1/2 of what it was.

For some reason, the temp in the cabinet has gone up about 2 degrees, not sure why, maybe it was losing some heat through the metal panels which are now insulated, but as a whole I would call it a success!

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