Building A Dedicated Server
Dedicated Servers > Guide > Hardware Components



Hardware Issues:

The hardware configuration of your dedicated server is of prime importance.

Later in this guide, we will also cover topics like whether you should go for a managed server or unmanaged one or if you should feel satisfied with a Virtual Private Server.

The basic reason why hardware configuration takes priority over these issues is that it plays primary role in budget allocation. Once we have a clear idea of how much will the hardware makeup cost, we can easily decide if we have enough to spare for managed services or need to drastically cut cost by opting for a Virtual Server.

Namely, the considerations are:

- Brand Name
Websites are mission critical applications. Hosting them requires careful consideration to the reputation of host server and the level of support attached to hardware failures. Companies like Intel, Sun, Cobalt have spent years of hard work in delivering the best hardware to their customers and meeting their expectations. Although servers made from generic parts are much cheaper, they do not put forward convincing reliability.

- Processor
The speed and built of your server's processor will definitely impinge on its ability to serve web pages in a flash. Make no compromise on the supremacy of your processor. Celerons are known to have problems when your applications grow large or when your hosting sales begin to skyrocket. Pentium 4's (P4's) have a larger cache and achieve improved performance. Another step up in the ladder is Xeon processor or specially Dual Xeon's that lure many dedicated server administrators.

- Amount of RAM
Web servers are RAM hogs. Upgrading RAM is one hardware addition that will pay off big. Thereby making it a valuable commodity when it comes to server hardware requirements.

When running a web hosting business, you are not only required to service website visitors but also run a myriad of other services such as DNS, SMTP, Shell Accounts, FTP etc. Your system will have to divide its memory resources among those tasks.

To answer "How much of RAM?", the rule of thumb is that "It should be enough to avoid swapping as much as possible". The Mod_Perl guide at TAM University gives a clear explanation of swapping process:

"When CPU needs to write something into a memory, but notices that it is already full, it takes the least frequently used memory pages (4k/page on average OS) and swap them out. Swapping out, means copying to the disk into a special partition or file called swap and deleting from the real memory. The another process asks CPU to bring another page, but CPU cannot find a memory page in the RAM, it was just swapped out, so it goes and brings it from the swap (swapping in). If memory is small, the swapping (in/out) happens too frequently, CPU becomes too busy to bring the pages in and out, HD working hard to read write the swapped out pages, and the whole performance is going down. Sometimes your swap partition can become full as well and your system might die."
http://www.coe.tamu.edu/cs/apache/mod_perl/hardware.html

- Hard Disk Technology
Size is not the only factor that differentiates one hard disk from the other. Hard disks also vary based on the technology that they are built on, specifically the access speed that these different technologies offer.

Every single request to a web server results in it accessing the hard disk. Workload is high and slow are the disks when matched with the capacity of processors. You need a HDD technology that offers higher disk speed. Thereby allowing your processor to read and process the disk with minimal waiting time, and fetch that second request in the queue.

SCSI (Small Computer System Interface) has a processor built into the drive which allows for faster read / writes and are thus recommended. The EIDE (Enhanced IDE) drives on the other hand, rely on the CPU.

- Mirrored Drives
All hard disks fail at some point or another. Therefore ensuring data redundancy is a must for any web host. When building the hardware configuration of your dedicated server, you must account for a backup drive. In the case of a drive crash, the server will experience no downtime since it has an immediate backup it can employ until the broken drive is replaced.

Other Sections In This Guide:
Server OS ... Before Anything Else, Hardware Issues, Managed VS Unmanaged Server, Considering A Virtual Private Server, Data Center & Server Connectivity Issues, Web Server Administration, DNS & BIND Overview, Remote Administration