This article discusses the understanding of linux. understanding of linux is a free open source operating system which is free for distributed under the GNU license. so you are allowed to install on your computer or copy and distribute it without having to pay. Linux is a derivative of Unix and can work on a variety of hardware ranging from inter koputer x86 to RISC. With the GNU (Gnu Not Unix) you can get the program, complete with source code (source code). Not only that, you are granted the right to copy as much as you want, or even change the code sumbernya.Dan was all legal under license. Although free, GNU license allows those who want to attract fee for copying and sending program.
The most important freedom of Linux, especially for programmers and network administrators, is the freedom to obtain the source code (source code) and the freedom to change it. This implies a few important things. Safety first, the second dynamics.
If commercial software does not allow you to know sumbenya code then you'll never know if the program you buy from them it is safe or not (often called security by obscurity). Your life in the hands of the vendors. And if there is a notice about the bugs of the commercial software, it is often too late. With Linux, you can examine the source code directly, along with other Linux users. The development of Linux users as an open community, making bugs will quickly known, and as soon as it did the programmer will fix the program. You yourself also determines the appropriate code in accordance with the basic hardware and other software to be implemented. Like a car, you can modify at will, even though the machine, in order to obtain the desired shape.
Disclosure of the source code also allows the operating system is growing rapidly. If a program with a closed system and is only developed by a particular vendor, at most about one thousand to five thousand people. As for Linux, with open source code, developed by volunteers around the world. Known bugs faster and penambalnya program (patch) more quickly available. Approach to the development of this operating system called Bazaar. Conversely Chatedraal very closed system and only focus on one or two developers only.
linux has now evolved into many distros (distributions), for example, is a distro Redhat, Debian, Suse. is currently a very popular linux distro in use in Indonesia is distro Ubuntu is derived from Debian.
Linux Virtual Server
The most important freedom of Linux, especially for programmers and network administrators, is the freedom to obtain the source code (source code) and the freedom to change it. This implies a few important things. Safety first, the second dynamics.
If commercial software does not allow you to know sumbenya code then you'll never know if the program you buy from them it is safe or not (often called security by obscurity). Your life in the hands of the vendors. And if there is a notice about the bugs of the commercial software, it is often too late. With Linux, you can examine the source code directly, along with other Linux users. The development of Linux users as an open community, making bugs will quickly known, and as soon as it did the programmer will fix the program. You yourself also determines the appropriate code in accordance with the basic hardware and other software to be implemented. Like a car, you can modify at will, even though the machine, in order to obtain the desired shape.
Disclosure of the source code also allows the operating system is growing rapidly. If a program with a closed system and is only developed by a particular vendor, at most about one thousand to five thousand people. As for Linux, with open source code, developed by volunteers around the world. Known bugs faster and penambalnya program (patch) more quickly available. Approach to the development of this operating system called Bazaar. Conversely Chatedraal very closed system and only focus on one or two developers only.
linux has now evolved into many distros (distributions), for example, is a distro Redhat, Debian, Suse. is currently a very popular linux distro in use in Indonesia is distro Ubuntu is derived from Debian.
Linux Virtual Server
1.Understanding the Linux Virtual Server
Linux virtual server (LVS) is a major open-source alternatives that provide solutions to make the system load balancing. As noted in the home site virtual linux server Project, Linux virtual server (LVS) is "a highly scalable and highly available server built on a cluster of realservers, with the load balancer running on the Linux operating system" The point of the real servers are machines computer that actually serve the existing request. Real servers can be connected using a LAN or WAN speeds. And machine spearhead server cluster is a director, in the form of a single server that connects real server with the client from the intranet or internet (outside the cluster system).
2. Linux virtual servers with OSI Layer Preview.
The basic concept of the network is never separated from OSI Layer, including virtual linux server system that works by balancing network loads. OSI is divided into seven layers, each of which contains a communication protocol for exchanging information between two or more computers, among others:
Physical layer (layer 1), a bottom layer that serves to mengubat data bits into electrical signals that will pass through a transmission medium.
Data Link layer (layer 2), this layer provides a data format, frame creation, control and data flow errors.
Network layer (layer 3), the main task of this layer is to address the provision of setting and managing network equipment network traffic.
The Transport layer (layer 4), the transport layer is responsible for the integrity of the data in the transmission process.
Session layer (layer 5), the layer is responsible for building, maintaining, and terminating sessions between applications.
Presentation layer (layer 6), serves to resolve differences of data formats, compression and data encryption.
Application layer (layer 7), is the uppermost layer of the OSI kelingkungan user interface.