When it comes to the advantages of linux, the first one is that he is open source, anyone can view his source code, which makes him especially safe, while windows is not open source, so you have to patch often, fix the vulnerability and so on.
Secondly, the linux kernel is well optimized, and no linux needs a right-click refresh button (red flag linux is added for Chinese usage), whereas windows is different, Microsoft's system is very complex, and the efficiency of operation is much lower compared to linux.
Although linux has no advantage in the desktop market (only a little more than 1% share), but his position in the server industry that is unbeatable (more than 20%).
linux takes up especially little system resources. Early linux, with 64M RAM, could run very smoothly.
I have only said a few points I understand the aspects of linux, and the advantages of linux there are many, many, specific still have to practice in their own understanding. Personally, I feel that if you rely entirely on Microsoft's increasingly user-friendly graphical interface, you will become more and more stupid, and ultimately become a slave to windows, which is a very scary thing, huh?
There are many advantages of Linux, the main ones being the following:
John Levin, CTO of eTrade, said, "Using a Linux operating system environment is almost 30 times cheaper than running and maintaining a UNIX operating system".
To summarize, there are several reasons:
Low software cost:
Because Linux is an open source operating system, in addition to the Kernel being free, many of its system programs as well as applications are free software, available for free on the Web. So its software costs are very low.
Low personnel training costs:
Linux was initially developed from college students, and enriched and improved by a heavy number of amateurs*** with it, so there are a lot of students and computer practitioners, who already have Linux skills. And in the low-end PC, PC servers can also be used, and the popularity is getting higher and higher. The talent pool is more than sufficient, and employers can more easily recruit people in this area.
Moreover, many enterprise-level users of the computing environment is low-end (PC, PC servers) and high-end (UNIX server or medium-sized or even mainframe) computers **** exist, different vendors of computers **** exist (involving operating systems may be Windows, IBM AIX, HP-UNIX, SUN Solaris, etc.), which requires that Computer system management and maintenance personnel with multiple operating system skills, and if the use of Linux, due to almost all grades of computer platforms support Linux, so technicians only need this kind of operating system training can be.
Low porting costs:
Linux can run on almost all computer platforms, including PCs, PC servers, UNIX servers, medium-sized machines, and mainframe computers, which creates extremely convenient conditions for porting the user's application software between different platforms.
For example, it is extremely common for enterprise-level users to upgrade their hardware platforms from small PC servers to higher-end UNIX servers, or even higher-end midrange or mainframe computers as their business continues to grow. In the past, because PC servers used the Windows operating system, while UNIX servers used the operating system, medium-sized machines and mainframes used special systems provided by vendors, so the software migration between different platforms may occur in the middleware software version replacement, application software recompilation, and even application software source code modification, which is likely to require relatively large The Linux operating system makes it much easier to migrate between different platforms.
Low management costs:
Similarly, because many enterprise users' computing environments are low-end and high-end computers***, and computers from different vendors***, if the operating system is standardized to Linux, the consistency of the system reduces management costs.
At the same time, any operating system is not perfect, there are some big or small loopholes or even errors. Since Linux is an open source software, there are many volunteer developers on the Internet working together, making the improvement of the functions of Linux and the discovery and modification of vulnerabilities very fast, reducing the risk of use and management, and thus reducing the cost of management.
High-performance:
The high-performance aspect of Linux is characterized by the low occupancy of Linux system resources and the advantages in high-performance computing.
2.3.2 Low operating system utilization
Linux is composed of a kernel and utilities on top of it. The kernel is responsible for managing the computer's resources, such as the processor and memory, and must ensure that the resources are allocated appropriately. When Linux starts, the kernel is loaded into memory and remains there until the power is turned off. Similar to most Unix or Unix-like systems, the Linux kernel is designed to be as small as possible, leaving much of the work to utilities outside the kernel. By taking advantage of this feature of Linux, users can customize how many applications they install when they install Linux, and in some cases they can install just one Linux kernel.
2.3.3 Advantages of Linux for High Performance Computing
The most widely used technology for high performance computing, such as scientific computing and oil exploration, is the High Performance Computing Cluster (HPC Cluster). It is a parallel computing cluster implementation method. In recent years, a new HPC system is rapidly emerging, which is the use of Intel platform computers running the Linux operating system to build HPC Cluster. due to the use of the Linux operating system, common hardware platform and standard network components, the nodes in the cluster are relatively inexpensive, easy to expand the realization of the cluster, so that you can get a higher price-performance ratio. Linux can be run on PCs, PC servers and other computers. Linux can be run on PCs, PC servers, which are traditionally monopolized by the Windows operating system. In this area, the emergence of Linux is like a spring wind blowing, which not only breaks the monopoly of Windows, but also is superior to the Windows operating system in terms of functionality and performance, and is closer to the high-end UNIX system. This allows low-end users to enjoy some of the benefits that only high-end systems can bring.
2.3.4 Highly scalable and maintainable
The scalability and maintainability of Linux gives Linux more advantages.
Extensibility
Standard Linux utilities have a large number of features that can be extended by modifying the source code, and Linux runs on a wide range of hardware platforms with similar interfaces, making it easy to port applications from one Linux system to another.
Maintainability
Because the Linux user interface is so similar to commercial versions of UNIX, almost all IT technicians have a good understanding of the interface. In addition, since Linux can run on a variety of hardware platforms, technicians familiar with Linux can easily manage applications on multiple hardware platforms. Currently, many versions of Linux, such as Red Flag Linux, have user interfaces that mimic those of Window, making it easier for non-IT technicians to utilize them.
Open standards
Linux is an operating system developed from open source code, which gives it an inherent advantage over other operating systems such as Windows and commercial UNIX versions. Linux has quickly become a relatively robust operating system, and is increasingly being used in a variety of business-critical applications.
The two main advantages are open source and stability.
Generally speaking, there are the following points: 1. Low software costs, because Linux is open source, so the many software on Linux are also open source and free. 2. Low porting costs, Linux can run on all computer platforms, such as personal PCs, professional servers, cell phones, etc. 3. High performance and high stability, Linux has open source contributions from all over the world, and has a high degree of stability. open source contributions from all over the world, with high stability and high performance. there are many more advantages of Linux will not be listed, in short, Linux is very popular, if you want to learn Linux, you can go to look at the book "Linux should be learned this way", which is very suitable for beginners to learn.
What are the advantages of linux and what are the Linux certifications?The advantages of linux
1. High degree of modularity
Linux kernel design is very delicate, divided into process scheduling, memory management, inter-process communication, virtual file systems and network interfaces in five major parts; its unique modular mechanism can be based on the user's needs, real-time insertion of certain modules or removed from the kernel, so that the Linux system kernel can be Tailored to be very small, very suitable for the needs of embedded systems.
2. Source code disclosure
Since the development of the Linux system has been tightly integrated with the GNU Project from the very beginning, most of its components come directly
from the GNU Project. Anyone and any organization can freely use the Linux
source code as long as they adhere to the terms of the GPL, providing maximum freedom for the user. This is also good for embedded systems, because embedded system applications vary greatly, and designers often need to modify and optimize the source code for specific applications,
so having access to the source code
is crucial for embedded system development. Plus, Linux is rich in software resources, and every kind of general-purpose program can be found on Linux, and the number is still growing. All this makes it very easy for designers to build on top of it. In addition, because the Linux source code is publicly available, users don't have to worry about security risks such as "backdoors".
At the same time, the open source code provides great convenience to educational institutions, which also promotes the learning, promotion, and application of Linux.
3. Wide range of hardware support
Linux supports a wide range of architecture microprocessors such as x86, ARM, MIPS, ALPHA, and PowerPC. It has been successfully ported to dozens of hardware platforms and can run on almost all popular processors.
Because there are many developers around the world contributing to the expansion of Linux, Linux has exceptionally rich driver resources, supports a variety of mainstream hardware devices and the latest hardware technology, and can even run on processors without a memory management unit MMU, all of which further promotes the use of Linux in embedded systems.
4. Security and Reliability
The kernel is efficient and stable, and the efficiency and stability of the Linux kernel has been verified in various fields.
A large number of network management and network service functions in Linux make it easy for users to set up efficient and stable firewalls, routers, workstations, servers, and so on. In order to improve security, it also provides a large number of network management software, network analysis software and network security software, etc..
5. With excellent development tools
The key to developing embedded systems is the need for a comprehensive set of development and debugging tools. Traditional embedded development and debugging tools are online emulator (In Circuit Emulator, ICE), which replaces the microprocessor on the target board, to provide a complete simulation environment for the target program, so that the developer can be very clear to the program on the target board working status, easy to monitor and debug the program. In-circuit emulators are very expensive and are only suitable for very low-level debugging. If the use of embedded Linux, once the hardware and software can support the normal serial port function, even if you do not use the online emulator, you can also be very good for the development and debugging work, thus saving a considerable amount of development costs. Embedded Linux provides developers with a complete set of tools (Tool Chain), can be easily realized from the operating system to the application software debugging at all levels.
6. Good network support and file system support
Linux from the birth of the date of the Inter is inseparable, support for a variety of standard Inter network protocols, and is easy to port to the embedded system. Currently, Linux supports almost all major network hardware, network protocols, and file systems, making it a great platform for NFS.
On the other hand, because Linux has good file system support (e.g., it supports Ext2, FAT32, romfs, etc.), it is a good platform for data copying, synchronization, and replication, which provides a solid foundation for the development of embedded system applications.
7. Fully compatible with UNIX
Currently, the tools and utilities included in Linux can perform all the major functions of UNIX.
But since Linux is not designed for real-time, this is the biggest drawback to its use in real-time systems. However, there are numerous free software enthusiasts who are working tirelessly on this and have achieved many results.
Stability and efficiency: Because Linux was developed from Unix, there are many similarities between Linux and Unix, not just in terms of the user interface and the way it operates, but also in terms of the stability and efficiency that Linux inherits from Unix's excellence. It is not uncommon for servers using Linux as their operating system to run continuously for a year without going down.
Low configuration requirements: Linux has very low hardware requirements, and it can run very smoothly on computers that are several years old. With Windows, you need to constantly upgrade your machine's hardware.
Free or little cost: Linux is based on the GPL, so anyone can use or modify the original code for free. Only if you choose a distribution of Linux made by certain vendors, you will need to pay a small fee.
Strong support: There are a lot of Linux enthusiasts who communicate and share good software, and there is a very open atmosphere.
Security: Linux has a very large user and community support, so it is very quick to find vulnerabilities and release security patches.
True multi-user: Linux realizes that different users **** the same login system, and resource sharing is fairer. Instead of a pseudo-multi-user operating system like Windows, if you need to log in more users, you either have to log out the current user or buy a multi-user license from Microsoft.
Linux has many other advantages, such as strong network support, easy console operation, and so on. While Linux does a good job overall, it still has some shortcomings.
Disadvantages of Linux:
No vendor-specific support: Because the software on Linux is distributed free of charge, there is no after-sales support.
The graphical interface was not good enough: this was probably the most important factor in the popularity of the Linux desktop. But as time passes, X-window is getting better and better. All of the major Linux distributions now work well as desktop computers.
Redhat certifications are introduced by Redhat, a well-known vendor in the server systems space. Red Hat certification is divided into three levels, the primary RHCT (Red Hat official in January 1, 2011, the abolition of the RHCT exam, changed to RHCSA), intermediate RHCE, senior RHCA. In addition in 2005, Red Hat launched a new advanced certification in the field of security: RHCSS.
RHCSA, is the abbreviation for Red Hat Certified System Administrator . It is Red Hat's entry-level certification and indicates that you can independently configure Red Hat Linux local clients, including installing and provisioning Linux for local use, local network clients, and troubleshooting local systems.
RHCE, short for Red Hat Certified Engineer. To earn this certification, you must pass the Red Hat exam, which is considered by the industry to be the most rigorous IT certification exam, and which is also known to be tied with CCIE as the best IT certification.
RHCE has earned its rightful place at the top end of the Linux certification spectrum. It can be said that earning the RHCE has become the most challenging certification that Linux users are bound to grab. Due to the popularity of Red Hat in the enterprise (at least 80% of organizations with Linux installations use Red Hat), there is a lot of useful knowledge that can be acquired through certification when learning Linux skills for specific applications.
Certification Magazine, the leading international certification magazine, concluded in an independent survey of the quality of popular IT certifications back in 2002 that RHCE certifications were number one in overall quality, teaching quality, and exam quality.
The famous IT certification website ranks the most popular IT certifications every year. Its authoritative reviewer, Becky Nagel, ranked RHCE sixth among the 10 hottest certifications in 2002, third among the 10 hottest certifications in 2003, fifth in 2004, third in 2005, and not only made the list for the fifth consecutive year in 2006, but also jumped to the top of the list. He had this to say about the RHCE: "If you want to prove that you have the highest level of Linux proficiency, there's no question that you should choose the RHCE, and that's not just because it's presented by a leader in the Linux industry, it's because to earn it you have to pass a rigorous pilot exam that tests the candidate's real-world skill level. This is not an exam that can be passed by rote memorization. We said this last year, and we'll say it again this year: if you're an RHCE, you should be confident in your abilities."
The launch of Red Hat Enterprise Linux products has further enhanced the value of the RHCE. This is exciting news for both those who have been RHCE certified in the past and those who are preparing to be RHCE certified in the future! Because in the past, RHCE only represents the top certification in the field of Linux. With enterprise Linux replacing the original Unix system at the core of large companies, RHCE certification will become the gold certification in the IT field, and RHCE will become synonymous with the top technicians in large companies.
RHCA, in 2004 Red Hat launched a new certification: Red Hat Certified Architect (Red Hat Certified Architect, referred to as: RHCA), is Red Hat's highest level of certification, including 5 exams: EX333 network services security management; EX401 system management and deployment; EX423 Directory Services and Certification; EX436 Enterprise Storage Management; EX442 System Optimization and Tuning. Each exam has a corresponding corresponding training (see below). Candidates must pass all five of these exams to receive a certificate. To sit for the RHCA exams, candidates must have earned the Red Hat Certified Engineer (RHCE) credential.
RHCSS, Red Hat Certified Security Specialist (Red Hat Certified Security Specialist) is also the successor to RHCE, which specializes in enterprise Linux security management, and has not yet been promoted in China.
What are the advantages of the linux systemAdvantages: open source, stable, powerful, flexible
Disadvantages: high barrier to entry
What are the advantages of Linux and the disadvantages of Windows?Personally, I think the advantages of the former are lower hardware requirements, almost all the software is genuine and free of charge, the interface can be set up according to their own preferences and operating habits, as for the disadvantages of the latter you can go to the Internet to look up
What are the advantages of the arts? The first time I saw this was when I was a student at the University of California at Berkeley.How to choose between arts and sciences?
1, interest. Interest is the greatest motivation for learning, whether it is a choice of arts, science, interest is the first prerequisite. As an example, Hao Yu, the top scholar in the 2001 college entrance examination, said in an interview, "My strength is science, but I grew up with a love of the arts, and has been maintained until high school, so I chose the arts and succeeded." So if you are interested in a certain area of your life, pay close attention to it or are more energized when you attend a certain class, consider taking a subject in that area. All in all it must be right to always put your interest first.
2, specialties. Specialty is the propellant of learning. It will make your learning handy, in the competition to win, is an important basis for the choice of arts and sciences. So how to discover your own special ability (talent)? If you feel particularly good about a subject, or use the same amount of time to get better results than in other subjects, or with a small amount of time to get results comparable to or better than other sciences spend a lot of time to get the results, if some of your own strengths and a close connection with a particular subject, all that means that you have the strengths and the ability to learn this subject. You should then consider which subject will better utilize and promote the development of your specialties.
3, results: results are the most practical basis for this choice. So it is very important to know the exact situation of your own performance in each subject. Politics group Mr. Wu said: students are very necessary to check their own results in various subjects, as well as the ranking of the results of the integrated arts and sciences, and to make a specific analysis and comparison, to see which of their own more competitive. Understanding the following three subjects in the Arts and Sciences selection is crucial.
Language: as the basis for learning all subjects, and each have a close connection, compared to the language and arts connection is greater, so the language is better, arts and science is slightly better than the appropriate choice of arts. However, if the science is better than the text, the selection of science also has an advantage, because most of the science students language is not strong, so the language is good, you can make their own competitiveness to improve a grade. (From the language group teacher's opinion)
Mathematics: the main subject of arts and science, in promoting competitiveness is comparable to the language, but the science of math is more demanding. Of course math also plays an important role in solving certain problems in the liberal arts (e.g., temperature, solar altitude, etc. in geography). （
English: Although its status in high school is comparable to the language, mathematics, but to the university is the highest status, no matter what to study, English is a necessary, mandatory subjects, good results in English, you can make your choice of arts and sciences a little freer.
4, ideal: everyone has an ideal, and it may be your goal. Then choose a subject that is close to your ideal, which will promote the study of this subject. For example, if you want to become an entrepreneur, then liberal arts and this ideal is closer, learning to learn liberal arts may be more positive, more active, academic performance may also be better.
5, society: observe, analyze social trends, understand the social demand for talent, because the arts and sciences selection is not only for the college entrance examination, in the long run, but also for their own future plans, lay a good foundation.
In short, each student should be based on their own actual situation, carefully analyzed, not due to some bad objective reasons and make the wrong choice, wrong life. This is the first time I've ever seen a person with a high level of skill and experience in the field.
What are the advantages of ultrasound? What are the applications of these advantages?First, it is very strong penetration is not easy to damage the object, and it is more than 20,000 Hz, will not affect the normal work of people.
Secondly, his propagation speed is fast.
It is used in medical treatment, such as ultrasound. Also used in detection, such as sonar, ultrasonic radar, metal flaw detector.