Choosing Server Hardware (Part II)

In our previous posts, we were talking about the server that needs to be replaced (an old Windows 2000 box), and how come your previous quote of $25,000 may have been rejected. We also went over choosing the hard drive, memory, CPU and hard drive. Here, we will discuss power requirements for all your equipment, licensing, and choosing an operating system.

Power

Power is something that should not be taken for granted, especially for a server that is housing all your company's important data! Does this mean you need a 1500W Power Supply for a server acting as a router? Don't be silly! You'll need to do some calculations to find the ideal power supply, and be prepared to buy another one with it.

In general, I calculate it using 15W per Enterprise class hard drive, 5W per memory module, then adding in what the processor recommends (see links on the previous posts). I would then add about 25% for the motherboard, then add 50% to that total to find the upper limit for the power supply. It may seem like a lot, but it really isn't. Power supplies are also rated by their efficiency. The more efficient it is, the cheaper it will be to run, and easier it is to sell to your boss. Depending on your chassis depends on if you use a standard ATX Power Supply, or if you need to use a custom power supply. If it's a custom one, make sure that you order a second one as a backup replacement, for when (or if) it dies.

While investigating the power supply, choose a chassis that will hold your motherboard and all your drives. Do you need hot swap? Only if your operating system and drive controller (on the motherboard or dedicated card) supports hot swap. I would almost always pass on this, for the simple reason that it's too easy to corrupt data. Other people will probably tell me that it's required, a great plus, super awesome... I would still prefer to power it down once in a while, especially when dealing with spinning hard drives. Make sure it has all the right power connectors too. You'll need enough SATA power connectors for each drive you plug in (remember the spare drives slots on the motherboard? Make sure you have a couple spare plugs on Power as well!), and usually just the 24-pin ATX connector, and a 4- or 8-pin CPU Power connector. If any of your add-in cards require special power, make sure you add those connections to what you require on a power supply as well.

Once you have the proper power supply picked out, you need a UPS to back up the power source. A UPS is a device that has a large battery in it, designed to keep the server running for a while after power has been cut off; some are built for extending the time the server stays up, and some are for telling the server to shut down safely as soon as power is lost. You will need to determine the requirements of your server to pick which is more important. UPSes are usually measured in Volt Amps, although some are in Watts. An example UPS Calculator can be found here, and will ask you what power supply you chose, as well as how much extra load you may have. Remember, you'll usually keep a network switch or Wi-Fi adapter on this as well, so you can talk to your server from your notebook or smart phone. Another sought-after feature in a UPS is that they will usually clean up the power for you, so spikes or shortages won't affect your server; yet another selling point when talking to your boss.

Licensing

Licensing is a big issue, especially if not done correctly. For the most part, Microsoft Windows Server software and Mac OSX Server software are the ones who require the most licensing on your server. If you are dealing with a small server, with less than 25 users, it's easy enough to purchase a Small Business version of Microsoft Windows Server (now called Windows Server Essentials); if dealing with more users, you'll need to find out which CALs (Client Access Licenses) you need; these are your licenses on top of the actual Server license. The CALs are counted by the number of users or connections into your server, not including clients such as over the web for a web site. The Windows Licensing Center is the best place to learn about CALs, as well as licensing other Microsoft products. They also have toll free numbers to call, where you can ask questions and get quotes. I highly recommend you spend some time figuring out your needs, and choosing the correct licensing for your organization.

Luckily, due to budget cuts, the only server software that LukeCorp was able to choose, based on the number of users, was Debian Linux. The cost of supporting 500 users with Windows Server was too much, and Linux can grow exponentially, and relatively easily once it's learned. With the decision to go with Linux, some Microsoft-only features will be lost: DirectAccess, a full Active Directory infrastructure, and Remote Web Access, for examples. Due to what the bosses wanted, we should be able to do the rest with Linux. That is what we will plan for.

Choosing the Operating System

Most companies will choose between Windows Server, and Linux. There are pros and cons to each, and the system admin will have to make an educated choice, and be able to stick to it! Whatever you choose, do not expect to switch on a whim, and without any sort of backlash from management and users during downtime. Both are different in how they are administered, what tools are installed by default, how much they are customized, and definitely by cost. If you've never used the Linux terminal, I'd recommend reading some tutorials and getting familiar with it. If you've never used Windows PowerShell or the Windows Command Prompt, I'd recommend some other tutorials. Feel free to Google other tutorials.

Why do I say to use the Linux Terminal, or Windows PowerShell and Command Prompt? Because most tasks are easier when done with just a keyboard. I've administered NT4 Servers, Windows Server 2000, Server 2003, Server 2008, Server 2008 R2, and Server 2012 servers. I've administered many Linux-based servers as well. The less I need to use the mouse when trying to get stuff done, the more efficient I am. Again, this is my personal experience and opinion; your mileage may vary. To connect to a Linux server, I use the free PuTTY program from my Windows computers; otherwise, I just type ssh username@servername command from my Mac OSX terminal, and other Linux servers. Easy as pie!

For administrating Windows Server products, I can use a variety of tools, some built in. The classic Remote Desktop Services is the most common way to connect, and gives you the full Windows Desktop. It is limited in its number of connections at a time, so make sure you log off when you are done, instead of just disconnecting every time.  You will almost always use this method, even for typing commands. If you prefer the Command Prompt only, you can connect with Telnet (you'll need to activate the Telnet server) to the server. As well, if you are only using Microsoft Management Console snap-ins, you can connect remotely to that service from your MMC console by right-clicking the element, and choosing 'Connect to another computer...'. These choices should give you access to what you need.

Do not take this decision lightly, as stated above. You will hear admins who love Linux, you'll hear admins who love Windows. You need to choose the right one for you and your team, since you'll be the ones who will be using the most features of it. To the end user, they see their files, they see their websites, they see their email. They don't care what you choose, but they know it better work.

In the next section, we'll talk about choosing your networking hardware, including switches, wireless, and routers. Stay tuned!