A server rack is another name for a server cabinet, a data cabinet or a rack mount. They are all cabinets for storing your hardware inside of, such as your servers and computing equipment. The idea is that it holds the hardware that is essential for daily business life but that does not need access to every day.
For example, if we scale it down and consider your home PC. If you were to remove the on/off button and have it wired to your desk and then have an external dvd/cd drive added to your desk, then your PC tower would very rarely need to be touched, moved or altered. It would then become a good candidate for being locked away in a rack mount. There are a few things you should consider when you are buying a rack mount. So I have created a quick article to give you an idea of what to think about.
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The price is a very big factor if you are not in need of a rack mount. If you can comfortably place your hardware in secure and ventilated places around your workplace, then there may not be a need for a rack mount. In that case it may only be an expensive cupboard in which to hold your hardware. In this case you may be better off buying a cheap one.
If on the other hand you have a priority, such as keeping systems cool keeping them together, keeping them secure, reducing noise, reducing energy consumption then you really need to base the amount you pay on how highly you prioritise those aspects.
For example if you have hardware that is jammed full of personal and private information, but is only updated and used infrequently, then you will need to prioritise security over efficiency. The amount you pay will then reflect that fact. In regards to efficiency and energy consumption, paying a little more now, may save money in the long run.
Your hardware may make a lot of noise. It may not be as loud as a car engine but it may become annoying for your staff in a quiet office. In this case, you may wish to buy a rack mount that has noise reduction built into it.
This is a basic lock and key situation in most cases. It is unlikely that you are going to block signals running through the hardware or escaping from them (such as how a wi-fi laptop may) but this can be adapted onto your rack if needed. There are also steps you may take to help stop EMP from affecting the hardware inside. Most people are going to want security in the form of lock and key. A good solid rack, bolted down with a decent amount of fire resistance should do the trick.
Ideally you are going to want as much air flowing between your hardware as possible. The items inside should be evenly spaced to allow air to flow and if you have a cooling and/or air extraction system fitted, then it will help maintain hardware efficiency.