วันจันทร์ที่ 22 กรกฎาคม พ.ศ. 2556

Data center







data center is a facility used to house computer systems and associated components, such as telecommunications and storage systems. It generally includes redundant or backup power supplies, redundant data communications connections, environmental controls (e.g., air conditioning, fire suppression) and security devices. Large data centers are industrial scale operations using as much electricity as a small town[1] and sometimes are a significant source of air pollution in the form of diesel exhaust.




Data centers have their roots in the huge computer rooms of the early ages of the computing industry. Early computer systems were complex to operate and maintain, and required a special environment in which to operate. Many cables were necessary to connect all the components, and methods to accommodate and organize these were devised, such as standard racks to mount equipment, elevated floors, and cable trays(installed overhead or under the elevated floor). Also, a single mainframe required a great deal of power, and had to be cooled to avoid overheating. Security was important – computers were expensive, and were often used for military purposes. Basic design guidelines for controlling access to the computer room were therefore devised.
During the boom of the microcomputer industry, and especially during the 1980s, computers started to be deployed everywhere, in many cases with little or no care about operating requirements. However, as information technology (IT) operations started to grow in complexity, companies grew aware of the need to control IT resources. With the advent ofclient-server computing, during the 1990s, microcomputers (now called "servers") started to find their places in the old computer rooms. The availability of inexpensive networking equipment, coupled with new standards for networkstructured cabling, made it possible to use a hierarchical design that put the servers in a specific room inside the company. The use of the term "data center," as applied to specially designed computer rooms, started to gain popular recognition about this time.
The boom of data centers came during thedot-com bubble. Companies needed fast Internet connectivity and nonstop operation to deploy systems and establish a presence on the Internet. Installing such equipment was not viable for many smaller companies. Many companies started building very large facilities, called Internet data centers (IDCs), which provide businesses with a range of solutions for systems deployment and operation. New technologies and practices were designed to handle the scale and the operational requirements of such large-scale operations. These practices eventually migrated toward the private data centers, and were adopted largely because of their practical results.
With an increase in the uptake of cloud computing, business and government organizations are scrutinizing data centers to a higher degree in areas such as security, availability, environmental impact and adherence to standards. Standard Documents from accredited professional groups, such as the Telecommunications Industry Association, specify the requirements for data center design. Well-known operational metrics for data center availability can be used to evaluate the business impact of a disruption. There is still a lot of development being done in operation practice, and also in environmentally friendly data center design. Data centers are typically very expensive to build and maintain.

Google Data Center






 Data Liberation Front is an engineering team at Google

 whose "goal is to make it easier for users to move their data

 in and out of Google products."The team, which consults 

with other engineering teams within Google on how to 

"liberate" Google products, currently supports 27 products. 

The purpose of the Data Liberation Front is to ensure that 

data can be migrated from Google once an individual or 

company stops using their services.

Computer Network




The meaning of the Computer Network.
Network Since the connection between two or more computers together. So that computers can communicate. "Computer network. Or network. Is a group of computers and devices. Were connected to the network can communicate. Information exchange. And equipment. Network sharing "network that has multiple dimensions. From a small computer connected by only a few machines. For use in the home or in a small company. To a large network connecting the Home Network or a home network, a LAN (Local Area Network) is a network of small computers. The introduction of computers and devices. Connections to each home. What was useful in fields such as computer use.

1. The use of shared resources means using devices such as printer sharing, ie there is only one printer. Everyone in the network can use this machine. The convenience and cost savings. I do not have to buy multiple printers. (There is a different type of computer time).

Two. Share files on a network computer is installed already. Using file-sharing or share files quickly and easily done. Without any storage device. All the issues in the migration capacity of media to it. Except in storage devices like hard core. If the space is full, it must be added.

Three. Communications. Computers connected by a network. Can talk to another computer. Through communication programs with the ability to use a computer as well. Or use the email form a network within the Home Network or Home Office, this will benefit many.

4 Internet using. Together. Every computer connected to the network.
Can use the Internet at all. With a single modem. Whether it is analog or digital ADSL popular today.

              Computer networking has become part of the organization. Institutions and home to the resource file and printer sharing requires the network is based. Networking means. Bringing two or more computers connected together to share the information. And shared resources such as files and printers. Network can be divided into three categories, namely.

First. LAN (Local Area Network).
Local system. The network in less than 10 kilometers to the communications network of the organization. Is a network within the same building or in different buildings in the distance.

Two. MAN (Metropolitan Area Network).
Network city The network to use the telephone communications network. Or the Communications Authority of Thailand. Well as in cities such as Kraftwerk Station on Sukhumvit. Are communicating with Kraftwerk at Station Rd.

Three. WAN (Wide Area Network).
Network wide. Also known as the World Wide network. The communication in the country. Across the continent or around the world. Require media (Media) to communicate the organization. Or the Communications Authority of Thailand. (Telephone dial-up / leased line Leased line / ISDN) (lntegrated Service Digital Network can deliver both audio and video at the same time).
 
 
Peer to Peer.
Peer to Peer network is a small network. For agencies. With less than 10 computer systems, Peer to Peer this computer. Can access any files stored on the device.
The Advantages of a Peer to Peer.
            First. Economical cost compared to other Network.
            Two. Could share the printer on each machine.
            Three. Easy to install. And can be expanded in the future as well.
Client / Server.
Networking Client / Server is the main computer called File Server (acting as a storage center for convenient data management) File Server must be left open or closed during use. Most computer users generally called Work Station.
The advantages of the traditional Client / Server.
First. Could share the printer on each machine.
Two. Has very good Security.
Three.'s Email messaging features as well.
Four. Share its resources can be allocated from the central point.
           

 
The Internet.
Modern computers have a role very seriously. It can be more diverse. Since the documentation. Budgeting. To the music on a computer, there's lots more. It has introduced a communications link to exchange information reference. An added benefit greatly because they can transfer data. This is extremely beneficial because it can be done quickly and easily.
                The structure and composition of the Internet.
                The Internet network, which was created by the Internet service provider or ISP (Internet Service Provider) and the computer network of the University of the various sub-networks (such as networked organizations. Incidentally, in the public sector. Have been linked by a transport network or information called Backbone Network Backbone.
Network Backbone may be performed by a company or group of companies, Internet Service Provider (ISP - operated backbone) or established and operated by the Joint (Consortium) as Thailand substances (Thaisarn) Network Backbone mainly used grid data. speed. The main features below.
First. Companies provide Internet (Internet Service Providers) is a company which provides connectivity to the Internet (Internet) for businesses in various educational institutions Guest etc. may be scope to serve customers in the surrounding area. Limited as the regional or provincial level or scope of services cover any national or international level. In addition to connecting to the Internet and corporate networks, Internet service providers, Internet service often have other accessories such as rent E-mail Box to store electronic mail (e-Mail).
Two. Network Backbone acts connected subnets together Network Backbone operated by the Company or any Group company, provides Internet or ISP - operated backbone or organization (Consortium) or its carrier phones. Backbone networks are well established for domestic connections, the connections between domestic and international services.
The Internet.
Currently, there are tens of millions of people worldwide use the Internet, and are being increasingly used as a first person. Each of which use different versions of the same computer. When we want to connect these computers together. It's important to have a common language. So that each computer can understand it. Technical language, this is called the protocol (Protocol) protocol to communicate on the Internet is called TCP / IP.
Computer network Internet communications between the Transmission Control Protocol (TCP) and Internet Protocol (IP), collectively known as TCP / IP data transmitted is divided into sections called Packet is addressed to a recipient with the designated. IP Address, suppose we send e-mail to someone, e-mail will be divided into Packet small multiple Packet Each Packet is addressed to the same receiver, then Packets These would run along with Packets of other people by making Packets of us probably are not sorted in consecutive trip wire of data Packets, they ran through the junction (Gateway) are provided by the Gateway (also called Router) will read the addressed. I will tell you the direction to the destination of each Packet that will run in the direction where the available Packet in the direction that would run on the new Gateway will be routed to the new Gateway to the next. Until the end, as we interact with machines in America. Gateway may have to pass on up to 10 Packet reaches the destination. Packets will also target those collected until the end. Sort the data to be restored to a perfect reality





วันจันทร์ที่ 15 กรกฎาคม พ.ศ. 2556

Home Network






Publisher eXP MEDIA.Chapter 2 Basic networking home network.Currently, the home network has been highly popular in network connectivity.Home network. Or small office. Since there is a connection.Easy and does not cost too much wastage. So I started turning.It to the attention of the network should start by networking home network.Before in this chapter will discuss the basics of networking home network carefully.This allows the reader to understand the function and importance of the various components.Home network is even more profound.Publisher eXP MEDIA.Known to the network home network.Home network. Network is a network that is ideal for use at home.Or small companies. The number of computers in a network is two or more.But not more than 10 machines (due to efficient data transmission reduction).To share resources, transfer or communicate information to each other. Therefore, the size ofNetwork, home network, so there is a small network of LAN.Most network home network LAN. Be used to form a connection.Computer "Peer to Peer" assigned to every computer on the network.All are entitled to equal rights. You can share and use the available resources ofEvery unit. Without the need to have a Server will act as administrator or allocated.Resources. To the computers in the network. Make a network connection.Home network easy. And do not need a computer to make a purchase.Server for the book is to offer a home network connection.With Windows XP, essentially allowing the reader to understand and act on the system.Network itself quickly without wasting time to study it.Network, home network connection.Publisher eXP MEDIA.Advantages and disadvantages of connecting a home network.Before we make a network connection to a home network, we should get to.Understand and know the pros and cons of the network connection is down. To be useful.Decisions. And solve problems that may occur during the action.Advantages.- The home network cost. Or the cost of installation and maintenance.Low system.- The network simpler. Do not waste too much time studying.- Can detect and correct problems on the network easily.- Each computer can share the same resources. It is used.Resources are cost-effectively and efficiently.- Communicate and transfer information to each other quickly and easily.- Ability to maintain and monitor computer usage in each unit.Disadvantages.- If you have many computers in a network to make efficient.Data reduction.- If the hub or switch may cause the entire network unusable.- Does not support large networks.- System security is low. Without limiting the rights of users.Each machine.Publisher eXP MEDIA.The definition of the protocol.Standardized protocols to computers on a network interface.Communication between them. The protocol is available on multiple formats. Each model can be.Developed for use in various types such as SMTP or POP protocol is used.The email from the mail server or RDP for communicating to controlFor remote desktop protocol that is widely used in the system.Network operating systems, including Windows TCP / IP NetBEUI and IPX / SPX.For Windows XP use TCP / IP as the primary protocol to communicate with the machine.Other networks.Introduction to TCP / IP.TCIP / IP (Transmission Control Protocol / Internet Protocol).Protocols that have been most popular. Especially in large networks.Interface zone due to a protocol that can support multiple standards.Platform is the operating system or any network. It is also a.Protocols to ensure that data sent to it will not be lost on the way, although there are some.The damage will be adjusted automatically to other road users. To send data.To a certain destination. The disadvantage of TCP / IP is not available.Guarantee that data sent to the destination machine when. This sometimes.Have to waste time waiting for a very long time. Also, what TCP / IP to form.Packets are not encrypted files for the security of the information that may be.No good or hackers detect some information. To damage.Computers in the network can communicate with the protocol.Publisher eXP MEDIA.The TCP / IP information is divided into small pieces. The package is called.Export routes to reach a destination on the right, there is a total package.These back to the same information. We can divide the function of TCP / IP.Into two parts, the TCP (Transmission Control Protocol) and IP (Internet.Protocol).TCP is responsible for checking the data transfer between the source computer.If the destination is interrupted or lost on the way, TCP will request information fromThe new data source. So that the terminal can receive data.CompletelyIP routing will monitor the traffic on the network andCheck the address of the destination machine. Using a size 4 Byte identifiers.Address, also known as "IP Address" enough.The performance of TCP / IP.Publisher eXP MEDIA.No. What is the IP Address.IP Address is a number assigned to a computer.Every network and all devices in the network. Provided that the numberIP Address to be assigned to every computer or device must not.Which overlap on the IP Address correctly will allow the computer.All the machines and equipment. Network as well as to transfer data back and forth.Between correctly by IP Address will be the address of the reference.Each computer for example, if computer A wants to send data files.Computer A to computer B computer B must be known or seen before.IP Address of the computer by the reference number B is correct then live.Protocol is the data transmission between the two machines.IP Address consists of four sets of numbers between each set of numbers.Are separated by dots, eg 192.168.0.1 computer converts the numeric value of the 4.Set into a binary before it is converted to the machine at all times.IP Address and the number is divided into two parts.- The use of a network number (Network Address).- The use of a number (Host Address).This number can be divided into two parts according to their usage.5 Class namely Calss A, B, C, D and E for Class D and E of the agency.InterNIC (Internet Network Information Center: The agency has been established fromThe U.S. government, which acts on the issuance and allotment of the numberIP Address of the computer network in the world) have been banned in use.Computer in the network is known or seen by the number IP Address.Publisher eXP MEDIA.IP Address Class A number in the range 0.0.0.0 to 127.255.255.255.Intended for distribution to organizations with large computer connected to the internal network.Mass.Class B IP Address numbers are in the range 128.0.0.0 to.191.255.255.255. Available for allocation to mid-sized organizations. Which can be connected.Computer on the network up to 65,534 machines.Class C IP Address numbers are in the range 192.0.0.0 to.223.255.255.255. Intended for small organizations and distributed to the user's computer.Most of the Internet. Can be connected to computers in the network.254 machine.Class D IP Address numbers are in the range 224.0.0.0 to.239.255.255.255. For a number of the IP Address Class is intended for use on the network.Multicast mode only.Class E numbers are in the range 240.0.0.0 to the IP Address.254.255.255.255. For a number of the IP Address Class is reserved for storage.In the future, it has not been implemented.Public IP and Private IP.On the Internet, we can get the IP Address allocated by the service provider.Internet (ISP: Internet Service Providers) to use the real IP Address.Also known as "Public IP" but for the network to use at home orDifferent offices, we will use the IP Address of the false or the "Private IP" which Class.Popular use is the Class C address range 192.168.0.0 to 192.168.255.0. By the user orAdministrators are able to set the number of IP Address Private IP.Manually.Publisher eXP MEDIA.Widnows XP home network to network.Windows XP is currently accepted as the appropriate operating system.In the home network, connect the network. Due to the stability.And commands. To support network connections, particularly home network.Which allows users to create and configure various To connect to the network.Easily without complicated steps and not have to waste time learning much.In particular, the Network Setup Wizard to enable the user to configure different.Quickly within a single command only. Whether for the network connection.The Computer Name and Workgroup to Internet sharing (ICS: Internet.Connection Sharing) or opening the firewall (Internet Connection.Firewall) to prevent attacks from the network, so no good with.Right above this. The content in this book are intended to be presented.Procedures, and how to connect to the home network is a network with Windows XP only.Windows XP has tools and commands. Many enables network connection easy.Publisher eXP MEDIA.Features of Windows XP that has been developed by Microsoft.To function. With network home network easily and efficiently.There are many ways.- The connections and configurations. Network to connect to a home network.It is very simple thanks to the Network Setup Wizard.- Support connecting networks wireless network (Wireless LAN) can beAs well, it allows us to configure and connect to wireless devices easily.- Can detect and correct problems on the network effectively.With performance features of the Network Diagnostics Tools.- Supports UPnp (Universal Plug and Play) perfectly.Makes connecting devices. Network as easy as possible.- High stability allows the network to operate efficiently.Trust not fall often.- Internet Connection Firewall feature protects against attacks.From those who may wish to create a disturbance to the network.Features of Windows XP for the network.Home network.Internet Connection Firewall protects a network from attacks, no good.Publisher eXP MEDIA.- To manage and share internet to a computer network byWith simple features of the Internet Connection Sharing (ICS).- Professional version can set the permissions to the network.Many user-level equivalent in Windows 2000, you can share files simultaneously.10 Connection and can be configured to work in a network.Workgroup or Domain optional.- Network Bridge are used to connect the two networks can be used.Compatible.- Have the ability to control the machine and help in the network.Remotely using Remote Desktop Connection and Remote Assistance.- A reliable security system at a certain level, such as the file system.NTFS (New Technology File System) allows the user to encrypt files Encrypting.File System (EFS) to not allow others to enable important data files.It can also determine the right to access the file NTFS Permissions.As well.New features of Windows XP Network Bridge connecting two networks together.