Resources for Quiet Rackmounts

Patrick

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Just wondering if anyone has found any good resources on methods to either quiet a rackmount chassis or actual rack enclosure. I was thinking about doing a piece on this.
 

john4200

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Jan 1, 2011
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I'm not sure I follow what you are proposing. Are you just talking about building a quiet computer in a rackmount chassis? That is no different, in principle, than building a quiet computer in a pedestal case. The same guidelines apply. Minimize the number of fans, use larger, slower spinning fans, minimize the number of openings in the case, have air going in one end, out the other. Use a quiet, high-efficiency power-supply. Use SSDs or slow spinning HDDs to minimize noise and waste heat. Add sound dampening material on the case walls if necessary.

The only thing I can think of that is unique to a rack-mount chassis is that they often have hot-swap bays, and hot-swap bays make it difficult to use the common methods of vibration-isolation for HDDs in pedestal cases.

For sound-dampened equipment racks, that is another story. You can buy them already made. But I have not seen any good articles for building one yourself. I imagine the main trick is to put in a lot of quiet, slow-spinning fans with carefully designed baffles in order to get sufficient airflow to cool all of the equipment without having the noise leak out with the hot air.

I suppose another alternative would be water cooling. You could always rig up water cooling for a rackmount chassis using similar equipment for a pedestal chassis.

Creating a huge water-cooled heat exchanger for an enclosed, sound-dampened equipment rack would be interesting.
 

S-F

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Feb 9, 2011
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Creating a huge water-cooled heat exchanger for an enclosed, sound-dampened equipment rack would be interesting.
Your water would need to be pretty cold and the interior radiator would need to be pretty big. For a while I toyed with the idea of making a sealed case like that. I big solid box filled with dynamat or something. I just ended up putting all of the radiators in the basement so there are no moving parts on my desktop aside from the fan in the PSU. I am about to WC my server on the same loop. I drilled holes in the Norco and put grommets in but haven't created manifolds for the tubing yet or gotten a water block. I plan on moving to a ground source solution instead of the radiators this summer and then maybe the sealed box will be feasible. I would really like to have a water and sound proof box for the server. Like a moron I currently have it sitting right below my kitchen sink in the basement.
 

Patrick

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nitrobass24: Maybe one of these days I will contact them about that. Quite a few corporate data centers do use watercooling (albeit a bit differently). My cousin actually is an engineer that builds them for a big search engine company.

S-F: we need pictures!

John: I have seen some pre-fabbed ones. 24U costs $5,000+

Big reason that I do not want to just watercool is that airflow is needed for expansion cards and drives anyway. This is more an exercise of determining how to live with screaming fans as I'm moving into doing more DP stuff. At $5,000/ 24U, this may be a really cool DIY candidate.
 

S-F

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Your water would need to be pretty cold and the interior radiator would need to be pretty big. For a while I toyed with the idea of making a sealed case like that. I big solid box filled with dynamat or something. I just ended up putting all of the radiators in the basement so there are no moving parts on my desktop aside from the fan in the PSU. I am about to WC my server on the same loop. I drilled holes in the Norco and put grommets in but haven't created manifolds for the tubing yet or gotten a water block. I plan on moving to a ground source solution instead of the radiators this summer and then maybe the sealed box will be feasible. I would really like to have a water and sound proof box for the server. Like a moron I currently have it sitting right below my kitchen sink in the basement.

Wouldn't you know it! The day after I posted this I came home to find the shut off valve for my cold line to the kitchen sink having burst. Went right to the basement to see water sheeting down conveniently onto my server. I immediately pulled the power at the outlet and brought the case upstairs. I let it dry out over a heating register for a week and just plugged it back in this morning. By some miracle I only lost one drive which my WHS can cope with.

RAID is not a backup. My backup is book upon book of DVD's and it sucks to have to restore from that! It takes weeks.
 

odditory

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Dec 23, 2010
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My backup is book upon book of DVD's and it sucks to have to restore from that! It takes weeks.
I decided long ago that the relatively low cost of extra harddisks is cheap insurance against what it would cost me in time to restore from optical media. you have to remember to put a pricetag on your time.
 
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leagle

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I decided long ago that the relatively low cost of extra harddisks is cheap insurance against what it would cost me in time to restore from optical media. you have to remember to put a pricetag on your time.
Same here. What I don't understand is the people that build 20 TB media servers, but then fail to build a backup server. As you said, reripping any decent sized collection is a tremendous waste of time when 2 TB drives can be bought for $60-$70. But, I know that people generally fall into one camp or the other, and they rarely see the wisdom of the other camp.
 

S-F

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Well in my case the DVD's I'm talking about aren't the originals. They are re encoded copies I have made and then burnt to disk. My originals are all in their cases in the closet. They only leave the case once and that's when I copy them for encoding. I have about 1,000 DVD's with re encoded material on them. Over the past decade my collection has gotten to be quite extensive. Also there are things like music, pictures and documents on there. The catch is that when you have 10 TB of data it's expensive to build an entire extra system for a backup. Drives don't cost that much but you also have to consider a case, motherboard, RAM, CPU and so on.
 

john4200

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Also there are things like music, pictures and documents on there. The catch is that when you have 10 TB of data it's expensive to build an entire extra system for a backup. Drives don't cost that much but you also have to consider a case, motherboard, RAM, CPU and so on.
It is usually a good idea to separate out hard to replace files like pictures and documents, from easy to replace files, like movies and music. That way you can easily do a thorough back up of the hard to replace files (which are probably relatively small in size).

As for people saying that the value of time to replace movies is high compared to the price of HDDs, they are likely not computing the expected value of their time properly. You cannot compare the price of an HDD today with the hourly rate of your time IF you lose an HDD in the future. You need to compute the value of your time IN EXPECTATION, provided that you lose an HDD of data. In many cases, it probably comes out a lot closer than you might think.

For example, I tend to rip blu-rays into MKVs without any additional compression, and I store an average of 80 MKVs per 2TB HDD. Using MakeMKV, it takes less than a minute of my time to rip an MKV (I typically do it when I am using the computer for other reasons, so it literally takes less than 1 minute of my attention to do the rip). Currently, I have 4 HDDs with movies on them. If the annual failure rate of the HDDs is 5%, and I replace them every 2 years (I'm always upgrading stuff), then the chances of having no HDDs fail in any given 2 year period is 66.3% (0.95^8). That is a 33.7% chance of 1 or more HDDs failing in that period (1: 28.7%, 2: 4.6%, 3: 0.3%). If I value my time at $100 per hour, and it takes 80 minutes of my time to replace the MKVs on an HDD, then the expected value of my time required is $133 x (0.287 + 2*0.046 + 3*0.003 ) = $51.60. So it is not even worth it for me to add a single parity disk, since the 2TB drives cost more than $51.60.

Of course, as the number of disks go up, the chances of a failure go up quickly. So somewhere around 5 or 6 disks it is going to be worth it to add a parity disk. That is easily done with FlexRAID.

But it is difficult to justify creating a completely separate backup server for movies, unless I think the chances of my current backup server being totally wiped are high. If it costs $500 + cost of HDDs to make a server, and $133 of my time to re-rip movies per HDD, then the relevant comparison is $500 + C * N to P * N * $133, where C is the cost of a 2TB HDD, N is the number of HDDs with movies, and P is the probability of losing all of the movies on the server. If N = 16, C = $80, then the critcal value for P is 84%. As long as the chances are lower than 84% that I will lose all the movies on the server, it is cheaper to not use a separate backup server for movies.

Note that this analysis does not apply to hard to replace files, like personal files or pictures I have taken. If I lose those without having a backup, then I cannot recover them, ever (well, maybe a drive recovery service could do it, depending on the type of loss, but even that is iffy). That is why it is a good idea to separate those types of files from the easy to replace files.
 
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S-F

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Feb 9, 2011
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Yeah. All of my pictures, documents, music and other hard to replace items are backed up in many locations. On my laptop. On my desktop. On redundant DVD's. And while I understand your point about your time as $, in my case I make absolutely nowhere near $100/hour. The job I was recently laid off from paid me $12 and given the economy where I live I was lucky to get even that. Also there is the down time. If I lost 1 drive (and my drives all have a LOT more than 80 movies on them since I re encode them) it would take me weeks to copy everything back over, even if I didn't do any format changing. I can't imagine trying to explain to my 4 yr. old son that he has to wait 10 - 70 minutes every time he wanted to watch a movie. It would be like Lord Of The Flies here by the end of the week. And also I have a personal preference to only remove the disk from it's case on the day I get it for copying only. I have lost thousands from children doing creative things such as rubbing a DVD on the coffee table.

We digress. Maybe this should be broken off into it's own topic since it's highly relevant to the nature of the forum.
 

john4200

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Jan 1, 2011
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Heh, where did you get the idea I was trying to guess a figure at which you valued your time? I just gave an example. Obviously you insert your own numbers for your time value and for the amount of your time it would require to replace your files.

It is interesting that the two values you mention are offsetting. Depending on the exact numbers you would use yourself, the decision could come out similar to the example. If you enter 1/8 of $100 as your time value, but it takes, say, 8 * 80 minutes to replace the data on a disk, then the cost of replacing a disk would be the same as the example calculation I posted. But if it took even longer to replace the data, then your disk replacement cost would be higher. The calculation is straightforward, you just have to plug in the numbers applicable to your situation.
 
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iceboi714

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Feb 27, 2011
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wow nice analysis there john...lol. But yea...I gave on up actually DVD backups...rip it to a hard drive and use a dvd emulator and that works for me. On the other hand my server is only on when I have sorted the data and I want it stored away. My main has 6TB total so I have plenty to of space for it. The only thing about DVD's that I worry about how it degrades. Before I had backups on there and a few years later I find there is an error when trying to read it. It was stored away in a cool place and I did not see any scratches on it. Luckily I had another backup that i never knew about. To each their own, but thats what I would do in my case. =D