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Currently we have about 8 or so in-house servers, all of which are Dell towers. We've never needed to upgrade them in a way other than more memory or a HD swap. There’s a 10 foot wide or so rack system that everything is on (servers, network hardware etc.) and it’s taking up a fair amount of space which is pretty limited in our office.

We're going to be upgrading two of the servers (backup and dev. web). What I'm wondering about is if there's any reason I should go for rack mounted or stick with towers. We don’t have a rack to put them in and I don’t see us getting one for awhile. My thinking is that it’s worth planning now so we can change over later, but I’m not sure if it’s ok to just stack rack mounted systems on each other, if there’s a real price difference that would make towers better or even something else I'm not thinking of. Our 2 newest Dell towers can be rack mounted if we got the hardware for it I think.

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10 Answers 10

If your servers will be in the room with other people, I suggest getting quiet tower systems. Rack servers are designed to keep cool under extreme conditions and have fans that sound like jet engines. Even putting the servers in a cabinet won't reduce the noise to comfortable levels.

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+1 If a low ambient noise level is important to you, having 5x10,000 RPM 1-inch fans in a 1U server isn't a good idea. – kmarsh Aug 18 '09 at 18:33
+1 I wasn't even thinking about noise, but that is a very good point. – Aaron Aug 30 '09 at 20:43

Tower servers are generally lower cost. I always buy rackmountable servers regardless. Converting from tower to rack is usually very pricey ($200-$500) even directly from Dell. Tower servers also take up more room as they are different sizes most of the time. Rack servers might be longer, but their width and height are standardized. Rack servers are sometimes a bit louder especially if you get 1U units. So keep that in mind.

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For your current servers, there's a good chance that they're of a form factor that will fit in a rack. We've used these "rails" to slip tower servers that were the right height, which most Dell towers are, into the racks on their sides.

Rack mount servers are more efficient space wise, but you always sacrifice something -- in this case, they're usually very loud.

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I've seen shelves used in racks to hold servers either on their sides or standing up. – Michael Kohne Aug 18 '09 at 18:53
Bear in mind a tower converted to a rack mount can be heavy (obviously depends on the tower and its components). If you've installed 8 towers into a single rack then getting to the higher boxes - sliding one out/removing it to perform some hardware swap out etc. might need a second person to help (I don't mean to sound all "health and safety"). – Dan Aug 30 '09 at 19:18

Looks like your main concern is space and that is one of the main benefits of using a rack to keep your servers in. You can have up to around 40 - 1U servers in about a 3x4 footprint (estimated cause I don't wanna measure our rack at the moment). You may even get more if you go with blades...It sounds like you are at a small company with 10 servers that are in the IT office with people so noise is an issue probably.

Needless to say if you are thinking of migrating your hardware to rack-mounted servers, this is going to cost the company money, and you will need upper-management to be on board with a project like this since they will only be looking at the bottom-line - how will rack-mounted servers help the company save money in the long-term? (or to quote Initech management "Is this good for the COMPANY?" :) Upper-management doesn't typically care if towers take up more space as long as there is space available, if they are quieter than a whole rack full of servers if the rack is in its own room, if they are easier to work on than towers, but they do care that towers are cheaper than rack-mounted servers...

It really depends on whether or not the company wants to make the jump to a rack or not and how good the current server hardware is at fulfilling the company's needs. IT need alone rarely drives company purchasing (or at least it shouldn't despite how cool new stuff is to us). Another factor to consider is, once you get your rack in place and fill it with servers is your cooling system going to need an upgrade as well? This will cost even more money. Do you have enough power in the room to handle a full rack? (I'd recommend building out the server room to handle a full rack at least even if you don't have enough servers to fill it up yet. The goal of most companies is to grow their business, after all).

Positive things to include when selling the rack form-factor to management are: 1) space savings 2) scalability will be easier due to #1

...actually that is probably it, all the other benefits are purely for the IT department. Rack systems are more scalable (static footprint but you can add more to the rack) so if you go through a period of rapid growth it will be much easier to expand your hardware to meet your needs. At some point I am sure, every company reaches a point at which they are at critical tower-server mass, and it just makes sense to go with racks because of the growing hardware pile - despite the upfront cost. You just need to determine if your particular company is at that point or not...You can look into other ways to reduce your hardware pile as well, such as virtualization - and you can usually implement a smaller-scale solution with free software such as ESXi or Hyper-V. I will leave you with this stupid saying I just made up - Once you go rack you never go back :)

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Dell does have servers that are designed to be either towers or rackmounted, if you are really concerned about flexibility. I will warn you though, they weigh a ton, are louder than a jet engine, and look like minitanks...

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they are also 5+ U when mounted... – shufler Aug 18 '09 at 18:35
Yes, they are beasts – RascalKing Aug 18 '09 at 19:54
We have 2 PowerEdge 2900s, when one of them was delivered FedEx wouldn't bring it up the stairs because it was around 80 pounds. – Brian Surowiec Aug 19 '09 at 4:19

Rack servers are really nice, once you do get a rack, all of the servers you have can eventually be converted to racks, and take up a fraction of the amount of space. Plus if you have room, you can mount your switches and firewalls on the upper portion of it, while keeping your rack servers on the bottom. If they are 1U servers, they hardly take up any space in the rack.

Now the other option for you to look at is blade servers. You buy the enclosure and then blades as you need them. It is a little more costly at first as you have to purchase the enclosure, but they are nice. Can can fit up to 8 servers in a very small area. I use the HP blade servers and with the enclosure gui and lights out technology, they are very easy to administer and work with.

I don't miss tower servers at all, and a few short years ago, that is all I had at one of my jobs.

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A number of people have commented on the increased noise that rackable servers have. Without a doubt, they are correct. However, it's possible to buy racks that reduce the noise considerably, to the point where it is comfortable to work near them. They are, however, double the cost of normal racks. Expect to pay upwards of 3000USD for a 30-40U noise-reducing rack.

Oh, and rackable servers all the way. So much easier to deal with.

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I always buy rackmountable regardless. They just make the job of keeping your server room tidier so much easier; the only downside of that is that you may find The Powers That Be trying to foist a smaller server room on you once they get an inkling of how much space they save!

Generally I like to see servers partitioned into separate racks: that's the rack that does our internal stuff, that's the rack that does our external stuff; that's the rack that holds our big databases, and so on. If you can match them up with who holds what admin role, then you can keep your DBAs physically away from your file server admins, and so on and vice versa. Especially nice if you can get fairly secure lockable racks.

It also makes the job easier if one group ever wants or needs to move to a different server room. You can identify their stuff instantly (it's in their rack!) and shut it down, move it, then bring it back up, all without having to worry about impact on other groups.

You can keep switches and other devices physically located in the same rack as the servers they are associated with for a nicely compartmentalised setup.

You'll probably find that with this sort of layout you won't be using the full extent of each rack, but that's extra space for that new box you always need to be able to slot in in a hurry.

The major disadvantage of rack servers though is that you lose a certain amount of flexibility, in terms of the fact that they're not as portable. Pulling out a box for decommissioning needs a bit more care, and you can't as easily bring a box off to a lab for testing should you ever need to. All in all though I say the pros outweigh the cons.

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Depends how many servers you plan to put in it. Once you have the rack installed, adding servers and devices will not increase the amount of space consumed at all, until it fills up and you need another rack.

Personally, I bought a server rack off a salvager on Craigslist for $150 and have two systems in it, along with all my networking gear. This is at home.

Many 4U Rackmount cases are basically standard ATX computer cases with a similar layout and compatible mounting points (fans, drives, etc). Therefore it's not difficult to set them up to run quietly if that's important. Just like any computer, it's a tradeoff with cooling.

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If you ware working around them and want rack servers DO NOT Get 1U equipment it is so loud, at the school I work out there are some 3/4U servers and a 1U firewall that overpowers all the other noise! so dont get 1U equipment for quietness.

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protected by Chris S Jul 26 '13 at 12:48

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