What is a server

American Computing Technologies is committed to helping you manage your computers and your information. Making a good choice on your server is critical because it is the foundation of your computing systems.

Some people will tell you there is no difference between a workstation and a server computer; this is not true. A server computer may run the same programs as a workstation computer but, that is where the similarities end.

Each component that goes into a server is designed to fulfill a specific requirement. As you read on, you should think of how each of these technologies will impact your business if it is not implemented. Lets look at what goes into a server.

Server Case

The Server Case needs to provide sufficient space to hold your hard drives, tape drives, and CD-ROMs. Except for very large companies, the server case should hold all of your hard drives and still have room for growth. The typical server case should hold between 10 and 20 drives. The most common reason for electronic components failure is heat. Every component in your server generates heat and lots of it. In fact, all of those components inside your server can generate enough heat to completely destroy your server without proper ventilation. Today's high performance hard drive is spinning at 10,000 RPM and requires direct cooling in order to maintain the drive warranty. Our server cases have between 4 and 15 ventilation fans and we always use direct cooling fans on hard drives.

Power Supply

The power supply in the server has to be able to provide a lot more power than a regular computer power supply.

Redundant Power Supply

A redundant power supply normally consists of two or three hot-swap power supplies in one unit that continuously supplies power to the server. In the event of a power supply failure, the other power supply unit(s) will handle the full load. The defective power supply unit can then be replaced without turning off the server. There is typically an audible alarm that alerts you that one of the power supplies is not functioning. Redundant power supplies offer one other important feature, two power cords. If the cords are plugged into different power sources, you can even survive a tripped breaker or a cord accidentally disconnected.

Motherboard

The motherboard is what the actual computer chips, memory and other computer cards plug into. It is the foundation of your server. Quality, features and the ability to control each part of the motherboard varies widely between motherboard manufacturers. Choosing the right motherboard can save you money and allow your server to be expanded in the future.

Hard Drives

Today there are two types of hard drives, IDE and SCSI. Desktop computers use IDE and servers use SCSI. SCSI drives are faster and smarter and IDE drives are cheaper.

SCSI Host Adapter

Hard drive controllers or host adapters come in a wide range of features and prices. Many motherboard companies provide a SCSI host adapter on the motherboard. Each SCSI host adapters can control up to 15 hard drives allowing room for expansion.

RAID

RAID (Redundant Array of Inexpensive Disks) is a technology that allows us to arrange multiple hard drives together to provide fault tolerance as well as very large logical drives. The idea of fault tolerance allows us to have a single hard drive failure without causing the server to fail.

RAID 1

RAID 1 or Mirroring is where we take two hard drives of the same size and mirror all information on both drives. If either one of these drives fail, the system will keep going.

RAID 5

Raid 5 or Striping with parity allows us to take a number of smaller, less expensive drives and make one large drive where you can have any single drive in the array fail, without your server failing.

Software and Hardware RAID

Some servers have a specialized computer located right on the SCSI host adapter. This is called hardware RAID. Some operating systems like Windows NT and UNIX provide support for RAID in their operating systems and don't require hardware to offer RAID.

So what is the advantage of hardware RAID? Hardware RAID reduces the load on the computer while software RAID consumes a significant portion of the computing resources. Hardware RAID generally offers additional features over software RAID. For instance, in the case of a hard drive failure, hardware RAID can automatically take a hot spare drive and replace the defective drive then rebuild the array. Hardware RAID does add between $1,000 and $6,000 to your server, so choose wisely.

Tape Drives

Tape backup is your last line of defense in the case of disaster. Some of the tapes should be stored off site in case of a disaster like fire or flood. Studies show complete loss of data from a disaster is enough to put many companies out of business. This can be even more costly if the data you lose belongs to someone else.