Windows Server 2008 - Understanding the minimum requirements

Every piece of software you install on your system uses resources, including the operating system. The three most important resources are memory, processing cycles, and hard drive space. You can use Windows Server 2008 without a mouse — it might not be very easy sometimes, but it’s possible. Theoretically, you need a DVD drive to work with Windows Server 2008, but you can even get around this requirement by booting from a network drive and installing from it. However, you can’t hope to run the operating system without three essential resources — it may not even start.

Of course, installing a server operating system and then just staring at it isn’t very exciting. You’ll want to install databases and applications on your server and use them to perform useful work. Consequently, you can’t install Windows Server 2008 on a machine with the minimum requirements and hope that it will do something useful. In addition to providing the minimum requirements for the operating system, you must also consider the requirements for each application you want to use. The following sections examine the three essential resources you need for Windows Server 2008.



Memory
Microsoft will try to tell you that the minimum memory requirement for Windows Server 2008 is 512 MB. Theoretically, you can run Server Core with that amount of memory, but it doesn’t perform many tasks. As a test, I tried this configuration on an older system and was able to install all the non- Active Directory roles. Active Directory really does require more memory. The full version of Windows Server 2008 doesn’t run with 512 MB — at least not well enough to do any useful work, based on some basic tests.

The Microsoft-recommended amount of memory is 1 GB, and the optimal amount is 2 GB, which is less than many people have on their Vista work stations. A more realistic amount of memory for the full installation of Windows Server 2008 is 4 GB for a small business, and you’ll want to move up from there as the size of your business increases. A small business that wants to save money may very well want to look at Server Core rather than obtain the hardware for the full installation; but as previously mentioned, Server Core doesn’t work as an application server.

At 4 GB, your server will have enough memory to perform basic tasks, such as serve files, perform printing, act as a DNS or DHCP server, and even support a basic Active Directory setup. You may still find that some applications don’t run. A 4 GB setup will probably support a small SQL Server installation, as long as you don’t install too many other operating system features. The 4 GB level is really just a good starting point for a serious server setup. Unfortunately, 4 GB of memory is also the maximum amount that you can install for the 32-bit version of the Standard edition.



Processor
Windows Server 2008 uses a lot of processing power to present the GUI. No, it doesn’t have the fancy Areo Glass functionality of Vista, but the GUI still chews up a lot of processing cycles. Consequently, you need to have some serious processing power to accomplish tasks. In this case, Microsoft recommends a 1 GHz processor as a minimum, which definitely doesn’t work unless you’re using Server Core. The 2 GHz recommended level works as long as you don’t expect the server to perform quickly. Microsoft recommends a 3 GHz processor for optimal performance. During information testing, I found that a 1 GHz system runs Server Core adequately enough to provide basic services and even support Active Directory. (As with the memory test, this test relied on an older system.) It doesn’t provide these services quickly — after about five users, you see even Server Core start to slow down significantly. The minimum full installation processor configuration you should consider for a small business with application server, domain controller, and database needs is a dual Xeon processor setup. The test system for this book relied on a dual processor setup running at 2 GHz (effectively giving the test system four processors).



Hard drive
Hard drive space is cheap. In fact, it’s the least expensive component of your server, so this is one area where you don’t have a good reason to cut corners. Get enough hard drive space for Windows Server 2008, your applications, data storage, a large paging file, and plenty left over for later expansion. (Computers with more than 16 GB of memory require more disk space for the paging file, hibernation, and memory dump files.)
Microsoft’s recommendation of 8 GB for Server Core or a full installation doesn’t work with today’s application requirements, and no one should seriously consider it. The recommended amount of drive space is 40 GB for a full installation or 8 GB for Server Core (because Server Core requires so much less hard drive space). Even the optimal size of 80 GB for a full installation is probably too small. A more realistic setup for a small business has at least 250 GB. As your business becomes larger, you need to increase the amount of available hard drive space.



Always consider the installation requirements for your applications before you begin installing the operating system. For example, an Exchange Server 2007 installation requires 2 GB of memory and a minimum of 1.2 GB of hard drive space. (See the specifications at http://www.microsoft.com/technet/prodtechnol/exchange/2007/evaluate/sysreqs.mspx for details.) In addition, Exchange Server 2007 requires a 64-bit version of Windows, so you’re limited on which versions of Windows Server 2008 you can use. Most vendors make the memory requirements for their applications easily accessible because they want you to have a good install. However, you should always consider the minimum requirements as bare minimums and perhaps hardly usable. It’s important to keep all the application installation requirements in mind as you work on your system.

It’s also important to consider the complexity of the hardware you use when estimating your resource requirements. For example, a Redundant Array of Inexpensive Disks (RAID) setup will cost you considerably more hard drive space than a standard setup does. Mirrored drive setups require twice as much space because everything appears twice. You should also consider the requirements of Storage Area Networks (SANs) and other storage technologies that your system uses.

Source of Information : For Dummies Windows Server 2008 For Dummies