Special topics: Windows to Linux: Part 1. Linux ideas

Differences and Similarities

Level: elementary

Chris Walden (cmwalden-at-us.ibm.com)
E-commerce architect, IBM Developer Relations
January 2004

IBM e-commerce architect Chris Walden willDeveloperWorksThe nine articles published in this article will guide you how to use your Windows Operating Skills in Linux. First, let's get to know the differences and similarities between Linux and Windows, and learn not to always solve the problem by restarting the system.

You have started to switch from Windows to Linux. This may be your decision, or you may have ". For whatever reason, the work methods and tools you are familiar with may be completely different. In addition, you may also need to train others to manage Linux easily. Management is by no means a step by step. successful management of the computing environment is a creative task. Achieving this transformation is like a skilled oil painter turning to sculpture.

Open standards enable Linux to follow the basic mode of Windows Management, which is indeed good news for users. Although the terms and tools are different, the fundamental principles are the same. Better news is that, when you get used to the Linux operating method, you will have a larger toolset to control and maintain your environment. The power of Linux lies in its stability and flexibility. Once you understand the concept of Linux, you can complete more tasks, automate more tasks, and perform more tasks remotely.

Linux and Windows have some similarities
Before discussing the differences between Linux and Windows, let's take a look at the similarities between the two.

Users and groups
Both Linux and Windows are multi-user operating systems. It can be used by many different users to provide separate environments and resources for each user. Control security based on user identity. You can control resource access permissions by group members, so that when the number of users is large, you do not have to set permissions for each account.

Users and groups can be centrally managed to allow multiple servers to share the same user and authentication data.

File System
Both Linux and Windows support multiple file systems. File resources can be shared with other clients through NetBIOS, FTP, or other protocols. You can flexibly organize individual file systems, and the Administrator determines where they can be accessed.

Ports and devices
Both operating systems support ports of various physical devices, such as parallel ports, serial ports, and USB ports. Supports various controllers, such as IDE and SCSI controllers. Linux also supports many standard hardware that are just listed.

Network
Both Linux and Windows support multiple network protocols, such as TCP/IP, NetBIOS, and IPX. Supports multiple types of network adapters. All have the ability to share resources through the network, such as shared files and printing. Can provide network service capabilities, such as DHCP and DNS.

Service
Both Linux and Windows provide services. The so-called service refers to the applications running in the background, which can provide some functions for the system and computers that remotely call the service. These programs can be independently controlled and automatically started during system boot. (Note: Linux follows the Unix habit, called this applicationDaemon,)

Differences between Linux and Windows
Although there are some similarities, there are still some fundamental differences in the way Windows and Linux work. These differences can be realized only when you are familiar with both, but they are the core of Linux thinking.

Linux applications target networks rather than printing
When Windows first appeared, the world was still a world of paper. One of Windows's great achievements is that you can easily see and print your work results. Such a beginning affects the later development of Windows.

Similarly, Linux is also affected by its origins. Linux is designed for network operating systems. Its design is inspired by the Unix operating system, so its command design is simple, or concise. Because plain text can work well across networks, Linux configuration files and data are based on text.

For those familiar with the graphic environment, the Linux server may be relatively primitive. However, Linux development focuses more on its internal functions than on the surface. Even in a text-only environment, Linux has extremely advanced network, script, and security capabilities. Some seemingly strange steps required to execute some tasks are confusing unless you realize that Linux expects to work with other Linux systems on the network to execute these tasks. The automatic execution capability of Linux is also very strong. You only need to design the batch processing file so that the system can automatically complete very detailed tasks. Linux's ability comes from its text-based nature.

Optional GUI
Linux has graphical components. Linux supports high-end graphics adapters and monitors, and is fully qualified for graphics-related work. Today, many digital effect artists are working on their design on Linux workstations, which previously had to be done using the IRIX system. However, the graphic environment is not integrated into Linux, but a separate layer running on the system. This means that you can run the GUI only or as needed. If the main task of your system is to provide Web applications, you can stop the graphic interface and use the memory and CPU resources used for your service. If you need to do some work in the GUI environment, you can open it and close it after the work is completed.

Linux provides graphical management tools and daily office tools, such as email, Web browsers, and document processing tools. However, in Linux, graphical management tools are usually extensions of the console (command line) tool. That is to say, all the work that can be done with graphical tools can also be done with console commands. Similarly, the use of graphical tools does not prevent you from manually modifying the configuration file. Its practical significance may not be particularly obvious. However, if you do anything in a graphical management tool, you can do it in the form of a command line, this means that those jobs can also be implemented by a script. Script-based commands can be automatically executed. Linux supports both of these methods at the same time, and does not require that you only use text or GUI. You can select the best method based on your needs.

The configuration file in Linux is a human-readable text file, which is similar to the INI file in Windows in the past, but essentially different from the Windows registry mechanism. Each application has its own configuration file, which is usually not put together with other configuration files. However, most of the configuration files are stored in a single place under a directory tree (/etc), so it looks like they are logically together. The text file configuration method allows you to back up, check, and edit the configuration file without using special system tools.

File name extension
Linux does not use file name extensions to identify file types. On the contrary, Linux identifies its type based on the file header content. To improve human readability, you can still use file name extensions, but this does not work for Linux systems. However, some applications, such as Web servers, may use naming conventions to identify file types. However, this is only the requirements of specific applications rather than those of Linux systems.

Linux uses the file access permission to determine whether a file is executable. Any file can be assigned executable permissions, so that the creator or administrator of programs and scripts can recognize them as executable files. This is conducive to security. Executable files saved to the system cannot be automatically executed, which can prevent many script viruses.

What is the kernel? Linux is actually just the kernel. It implements multi-task and multi-user functions, manages hardware, allocates memory, and activates the running of applications. For beginners, the most important thing is to understand that an odd number of kernel versions (such as 2.3, 2.5, and 2.7) are experimental and under development kernels. Stable and officially released kernel versions are even (such as 2.4, 2.6, and 2.8 ).

Rebooting is the final means
If you have been using Windows for a long time, you may be used to restarting the system for various reasons (from software installation to service troubleshooting. In Linux, your habits need to be changed. Linux follows the Newton's law of motion in essence ". Once it starts running, it will remain running until it is affected by external factors, such as hardware faults. In fact, the design of the Linux system does not cause the kernel to crash, so you do not have to reboot frequently (relative to the design of the Windows system ). In addition to the Linux kernel, you do not need to reboot the system to install, start, stop, or reconfigure other software.

If you re-boot the Linux system, the problem may not be solved, and it will make the problem worse. Learning and understanding the Linux service and running level is the key to a successful solution. The most difficult thing to learn about Linux is to overcome the habit of re-guiding the system.

In addition, you can remotely complete a lot of work in Linux. As long as some basic network services are running, you can access the system. In addition, if a specific service in the system has a problem, you can continue to run other services while performing troubleshooting. This management method is very important when you run multiple services on a system at the same time.

Command case sensitive
All Linux commands and options are case sensitive. For example,-RAnd-RThey will do different things. Console Commands are almost all in lowercase. We will give a more detailed introduction to the commands in "Part 1. Console crash course.

How should I locate Linux?
It is troublesome to change from Windows Management to Linux management. However, as a Windows administrator, you have your own advantages. Your understanding of how computing works is still available. Whether you can become a successful Linux administrator depends on your understanding of the differences between the two and the adjustment of operating habits.

Many changes in Linux compared with Windows are beneficial. Idle GUI overhead is returned to the service. Tasks can be scripted and automatically executed. The configuration file is text-based and readable. In most cases, you do not have to reboot the system. In fact, you should suppress the impulse to reboot the system.

References

• From DOS/Windows to Linux HOWTO provides quick start information for those with DOS or Windows backgrounds.

• To start using IBM software on Linux, speeding up your Linux application development will provide you with the best reference materials. You can find installation tips and references for various applications such as DB2, Lotus Domino, WebSphere Application Server, and WebSphere Studio. You can also log on to get the free Linux software evaluation kit, which contains trial software and training materials.
• ToDeveloperWorksFrom here, I will continue to learn the basic concepts of Linux on the Linux page.
• "Linux user Technical FAQ "(DeveloperWorksJuly 2001) can also help you smoothly transition from windows to Linux.
• The Linux documentation project is a Linux document warehouse. It collects documents including separate software, howto documents, FAQs, and so on.
• Linux Online! Provides unbiased Linux news and information.
• O 'Reilly network is an excellent resource for Linux technical books.
• The Linux at IBM site provides software, links, end-to-end Linux Solutions, user references, IBM alliances/Linux product partners, and IBM open-source products. For more information, see learning Linux and Linux education on the Linux at IBM page.
• IBM provides professional certification services for Linux and UNIX and Linux hardware and various software systems (including IBM products.
• IBM partnerworld provides marketing and sales support for IBM business partners.
• Linux lens is a portal for IBM Business Partners to quickly access Linux.
• InDeveloperWorksYou can find more references for Linux developers in the Linux area.

About the author Chris Walden is an IBM Developer Relations Technical Consulting (also knownDragonslayersE-commerce architect, which provides education, implementation, and consulting for IBM business partners. He is dedicated to Linux-related work and will publicize the benefits of Linux to people around him as soon as he has the opportunity. In addition to fulfilling the responsibilities of his architect, he is also proficient in various fields of Linux infrastructure servers, including files, printing and other application services in the hybrid platform user environment. Chris has 10 years of experience in the computer industry. From field support to Web application development and consulting, he has been involved in various fields. You can contact Chris via cmwalden-at-us.ibm.com.