Introduction to Servers

Servers

A server is a hardware device which performs services for the clients connected to it. The service delivered depends on what the server is being used for. For example, an email server routes and stores email for its clients. A server with a large storage capacity might be used to store large files for its clients.

3 server form factors:

• Tower
• Rack
• Blade (newer form factor packs more processing power in a smaller space)

The choice depends largely on the number of clients being served. A small tower server might handle 1-10 clients with ease. A large office complex with 1000's of connected PC's would require either a rack or blade setup.

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Tower

In theory any computer can be used as a server. You could take an old PC in your house and use it to serve up media files maybe store your mp3's?

A tower case is significantly larger than a standard ATX case. Tower servers are typically used for small business with perhaps <1,000 users.

Example of a tower server

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Rack

A server rack looks like a tall cabinet with slots for components to slide in. A standard sized component for a rack is 1U (19 inches wide X 1.75 inches tall) and a rack cabinet is 42U. A rack is a much more practical solution for squeezing a large amount of hardware into a small space. A server rack can be expanded to handle 1,000's of users.
Example of a rack Server

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Blade

Blade technology is essentially an improvement on the traditional server rack. The "blades" contain the bare minimum of components. The blade case supplies all the power and network connectivity and cooling. This means you can get up to 100 processing blades in the same space as a 42U rack.The blades work together and are controlled by the operating system.

Example of a blade server

Each particular type of server is generally defined by its configuration and software which enables it to communicate with intermediate client machines.

According to the services it provides, Servers can be classified into many types, few are listed below:

1.Application servers

2.Audio/Video servers

3.Chat servers

4.Fax servers

5.FTP servers

6.Groupware servers

7.IRC(Internet Relay Chat) servers

8.List Servers

9.Mail servers

10.News servers

11.Proxy servers

12.Telnet servers

13.web servers

14.Database servers

15.Staging servers

16.Backup servers

17.Directory server(Enterprise access servers)

18.DNS/DHCP servers

19.Management server

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Phew! ;-)

Server-Client Network Model

If you are interested to know how Client machines are connected to Servers, then you should have a look to the below Network diagram. You will find lot networking concepts applied to this model. We will cover these advanced Networking concepts in our future sessions as well.

- This was just an introduction session. After completing few basic concepts, in coming sessions, we  will focus on Server Configuration, Management and Administration part. Thank you !