Types of Storage

Holla a todos..!!

Classification of Storage Devices:

• Primary/Permanent 

• Secondary/Temporary

• Tertiary/Off-line 

1. Primary Storage is further classified as:

Magnetic Storage: 

A. Hard Disk Drive

Types of Hard Disk Drives:

•  PATA/IDE: Parallel Advanced Technology Attachment/Integrated Drive Electronics

•  SATA: Serial Advanced Technology Attachment 

•  SCSI:  Small Computer System Interface

•  SSD:  Solid State Drivers

B. Floppy Disk Drive

C. Tape Drivers

Optical Storage:

• CD:Compact Disk

• DVD:Digital Versatile Disk

• BLU-RAY

• HD DVD: High DVD

• USB:Universal Serial Bus

2. Temporary Storage

 Example: RAM because when you switch the computer off, all the information that was stored will be lost. 

3. Tertiary/Off-line Storage

Tertiary: It includes Robotic mechanism which will mount & dismount removable mass storage media into storage device ,i.e; data is copied before use.Examples: tape libraries & optical juke boxes.
Off-line: Most of the secondary & tertiary media are also used for offline storage as it needs human interaction where media is stored & disconnected.Examples: Zip Disks, Flash memory devices.


Storage Hierarchy:

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Servers - Operating System requirements & Types

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Server: A system's software & suitable hardware that responds to requests across a network to perform specific task on behalf of clients. Services can be either private users inside a large organization or to public users via internet.

A servers operating system should have following:

• Ability to reconfigure & update without restart 
• Backup facilities at regular intervals
• Automations; like daemon which runs in background process
• Tight security with authentication as *GUI is optional

Types: Depending upon the requirement different servers provide different client support services. Information about some of the important client model based servers are discussed here.


1. Name: DNS (Domain Name System) server translates domain names & host names into IP addresses needed for purpose of locating computer services & devices worldwide.

2. DHCP: Dynamic Host Configuration Protocol  is a network protocol that enables a server to automatically assign an IP address to a computer from a defined range of numbers configured for a given network. DHCP assigns an IP address when a system is started. 

DORA Phases:

• A user turns on a computer with a DHCP client. 
• The client computer sends a broadcast request called a DISCOVER looking for a DHCP server to answer. 
• The router directs the DISCOVER packet to the correct DHCP server. 
• The server receives the DISCOVER packet. Based on availability and usage policies set on the server, the server determines an appropriate address if any, to give to the client. The server then temporarily reserves that address for the client and sends back to the client an OFFER packet, with that address information. The server also configures the client's DNS servers. 
• The client sends a REQUEST packet, letting the server know that it intends to use the address. 
• The server sends an ACKNOWLEDGE packet, confirming that the client has a been given a lease on the address for a server-specified period of time.

3. Proxy: A server that acts as an intermediary between a workstation user and the Internet so that the enterprise can ensure security, administrative control, and caching service. Web proxies can also filter the content of Web pages served. Some applications,which attempt to block offensive Web content  are implemented by Web proxies.

4. FTP: File Transfer Protocol  is a standard Internet protocol for transmitting files between computers on the Internet. Like the Hypertext Transfer Protocol (HTTP), which transfers displayable Web pages and related files and the Simple Mail Transfer Protocol (SMTP), which transfers e-mail, FTP is an application protocol that uses the Internet's TCP/IP protocols. FTP is commonly used to transfer Web page files from their creator to the computer that acts as their Server for everyone on the Internet. It's also commonly used to download programs and other files to your computer from other servers.

 World Wide Web is the system of interlinked hypertext documents accessed via internet, it is not mandatory to use WWW before making webpages where as http/https are required to specify communication to be used for request and response,where http(s) is for security usage.

*GUI- Graphical User Interface

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Introduction :Why Unix & Why not Windows in the Corporate World??

  Hello ....!!   
 Hola a todos... :-) 

       I have brought you easy way to learn Linux & also some of the interesting facts about Linux.

1.Linux/GNU: Anybody can edit,read,change in anyway as it is open sourced license,source code is openly shared.

   Windows: Source code is copyrighted & hidden from users (for making profit).

2.Command line interface,noted along side in metadata marking an execute permission,built in Security;

  Graphical User Interface, o/s designate executable files by file name extension(easy to be hacked).

3.Installed on any machine, from ARM based to Super computers including mainframe,micro comp's;

windows cannot be installed everywhere.

4.Linux possesses greater processing power than windows, as it requires less admin & maintenance ,

no software upgrades purchase needed.

       Facts about Linux:

• Unix is the leader in serving web, 90% internet relies on Unix running on Apache.
• Android system is wide & it is built on Linux kernal
• Latest Mac OS X 10.8 is a Unix o/s build on technology
• BSD, a flavor of unix servers are best marked o/s servers
• Mozilla Firefox web browser is application used with Linux systems

      Millions of users having lack of knowledge what an o/s have been using,window's o/s was given while buying their PC's, many people doesn't know there are o/s other than windows.

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