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This article mainly introduces what is the difference between Centos and Redhat, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor take you to understand it.

A brief introduction to CentOS

CentOS is short for Community ENTerprise Operating System, and many of us call it the Community Enterprise operating system. No matter what you call it, it is a distribution of the Linux operating system.

CentOS is not a brand new Linux distribution, and when it comes to the name Red Hat, everyone seems to have heard of it. There is an enterprise version of the product in the Red Hat family, which is Red Hat Enterprise Linux (hereinafter called RHEL), and CentOS is a clone of this RHEL. RHEL is a Linux distribution adopted by many enterprises, which can only be used by paying for Red Hat, and can get paid services and technical support and version upgrades. CentOS can build a Linux system environment like RHEL, but it does not need to pay any fees for products and services to Red Hat, and does not get any paid technical support and upgrade services.

Among the products of Red Hat, there are Red Hat Linux (such as Redhat8,9) and Red Hat Enterprise Linux, which are issued for enterprises, which can be obtained and used free of charge through the network FTP, but in 2003, Red Hat Linux stopped publishing, and its project was replaced by the project Fedora Project, and issued under the name Fedora Core and provided to ordinary users for free use. The Linux release of Fedora Core is updated very quickly, and a new version will be released in about half a year. The current version is Fedora Core 6, this Fedora Core experiment has a strong flavor, each release has new features added to it, the successful results will be used in the release of Dow RHEL. In spite of this, the unstable products that are frequently improved and updated are not the best choice for enterprises, and most enterprises still choose paid RHEL products (which has a deep meaning, for example, enterprises use Linux to make money, the money earned is returned to enterprises, funds flow among enterprises, return to society, improve service standards, etc.).

Most of the software packages that make up RHEL are released based on the GPL protocol, which is often called open source software. Because of this, Red Hat also follows this agreement and publishes the software package that constitutes RHEL. As long as it follows the GPL protocol, anyone can redevelop and release on the basis of the original software composition. CentOS is a Linux distribution version that clones and reproduces the composition of RHEL on the basis of RHEL release. There are not only CentOS clones of RHEL, but also White Box Enterprise Linux and TAO Linux and Scientific Linux (nothing else has been heard of, have they? ).

Although it is a RHEL clone, it is not exactly the same, and the clone is 100% interchangeable (really? ). However, there is no guarantee that the software corresponding to RHEL will work 100% on CentOS. And security vulnerability fixes and software package upgrades correspond to RHEL's paid services and technical support, with days, weeks and months of delays (in fact, it doesn't seem too slow).

Characteristics of CentOS

In the full name of CentOS, we can see Enterprise OS, that is, enterprise system, this enterprise system is not an enterprise system, but it can provide the elements needed by enterprise applications.

For example:

A stable environment

Long-term upgrade and update support

Strong conservatism

Large-scale systems can also perform well.

CentOS meets the above elements, and distributions that meet the above elements also have Fedora. Fedora and CentOS are very similar, but for CentOS, Fedora provides more new functions and software, releases and updates quickly, which adds a lot of work in terms of stability and management. The system environment needed by the enterprise should be an efficient and stable system environment and a system environment that can be used for a long time after a construction, so the system environment that is updated and released frequently like Fedora does not correspond to the application of the enterprise. On the other hand, CentOS can meet the needs of the above enterprises. Among the many cloned versions of RHEL, CentOS is very outstanding.

The relationship between CentOS and RedHat

When RedHat is released, there are two ways: binary distribution and source code distribution. No matter which distribution method it is, you can get it for free (for example, download it from the Internet) and release it again. But if you use their online upgrades (including patches) or consulting services, you have to pay.

RedHat has always provided a way to distribute the source code, and CentOS is to recompile the source code released by RedHat to form a usable binary version. Since the source code of Linux is GNU, it is legal from obtaining the source code of RedHat to compiling it to a new binary. It's just that RedHat is a trademark, so the RedHat trademark must be removed in the new release.

RedHat's attitude towards this release is: "We are not really opposed to this release. The users who really pay us pay attention not to the system itself, but to the business services we provide." So, CentOS can get all the functions of RedHat, even better software. But CentOS does not provide commercial support to users, nor does it bear any commercial responsibility.

If you want to transfer your RedHat to CentOS, because you don't want to pay for RedHat upgrades. Of course, you must have rich experience with UNIX, so the commercial technical support of RedHat is not important to you. But if you are a pure business enterprise, it is recommended that you choose RedHat software and purchase corresponding services. In this way, you can save your IT management expenses and get professional services.

In a word, whether you choose CentOS or RedHat depends on whether your company has the appropriate technical strength.

1. CentOS can be understood as RedHat AS series! It is released after the improvement of RedHat AS! There is no difference between various operations, uses and RedHat!

2. CentOS is completely free, and there is no problem of requiring serial numbers like the RedHat AS series.

3. CentOS's unique yum command supports online upgrades and can update the system instantly, unlike RedHat, which costs money to buy support services!

4. CentOS fixed a lot of RedHat AS's BUG!

5. CentOS version Notes:

CentOS4.0 is equivalent to RedHat AS4.

CentOS4.1 is equivalent to RedHat AS4 U1.

CentOS4.2 is equivalent to RedHat AS4 U2

CentOS4.3 is equivalent to RedHat AS4 U3.

CentOS4.4 is equivalent to RedHat AS4 U4.

Redhat series products

Redhat has two major Linux product lines:

One is the free Fedora Core series, which is mainly used in the desktop version and provides support for more new features.

(note: among the products of RedHat, there are RedHat Linux (such as Redhat8,9) and RedHat Enterprise Linux, which are issued for enterprises, which can be obtained and used free of charge through the network FTP, but in 2003, RedHat Linux stopped developing, which is why there is no Redhat10. Its project has been replaced by the project Fedora Project, and issued under the name Fedora Core and provided to ordinary users for free. Fedora Core this Linux release updates very quickly, about half a year there will be a new version, the current version is Fedora Core 6, this Fedora Core experiment has a strong flavor, each release has new features have been added to it, the successful results will be used in the release of Dow RHEL. Even so, unstable products that are frequently improved and updated are not the best choice for enterprises, and most enterprises will choose paid RHEL products.)

Second, the charge of the Enterprise series, this series is divided into: AS/ES/WS and other branches. Red Hat Enterprise Linux: the enterprise version of redhat, written by Jane: RHEL. The following versions are included:

1 、 Red Hat Enterprise Linux AS

Red Hat Enterprise Linux AS (Advanced Server) is the most high-end product in enterprise Linux solutions, which is designed for enterprise related applications and data centers. Red Hat Enterprise Linux AS is the only product that supports IBM I-series, p-series and z-series / Smure 390 systems. On the Intel X86 platform, the Red Hat enterprise Linux AS can support more than 2 CPU and memory larger than 8GB. A typical Red Hat enterprise Linux AS application environment is as follows:

Database and database application software

WEB and Middleware

CRM, ERP,SCM

2. Red Hat Enterprise Linux ES Red Hat Enterprise Linux ES (Entry Server)

Provides a server operating system for the Intel X86 market from enterprise portals to enterprise middle-level applications. It supports 1-2CPU and systems with less than 8GB memory. It provides the same performance as Red Hat enterprise Linux AS, except that it supports smaller systems and lower costs. A typical Red Hat enterprise Linux ES application environment is as follows:

Corporate WEB Architectur

Network edge applications (DHCP, DNS, firewall, etc.)

Mail and document / print services

Small and medium-sized databases and departmental application software

3 、 Red Hat Enterprise Linux WS

Red Hat Enterprise Linux WS (Workstation) is the desktop / client partner of Red Hat Enterprise Linux AS and ES. Red Hat Enterprise Linux WS supports 1-2CPU intel and AMD systems, which is the best environment for desktop applications. It contains a variety of commonly used desktop applications (Office tools, mail, instant messages, browsers, etc.), can run a variety of client-server configuration tools, software development tools and a variety of applications (such as EDA and Oil/Gas applications). Red Hat enterprise Linux Ws and server products are compiled from the same source code, but it does not provide network services (such as DNS and DHCP), it is only suitable for client applications.

(note: Advanced Server, abbreviation is AS. Based on the standard Linux kernel, AS enhances its performance, improves its reliability, and integrates many common server drivers. It can easily identify devices such as disk array cards of common rack servers such as IBM/DELL/HP. 2.x/3.x/4.x, the main version of AS, which is what we call AS3/AS4, has several upgrades for each version. For example, after the earliest launch of AS4, some updates were encountered. AS4 Update1 will be released at this time, and AS4 Update2/Update3 will appear one after another, such as AS4u1/AS4u2/AS4u3 and so on. This is also very similar to Microsoft's release form, Microsoft's Windows NT4 from SP1 to SP6,Windows2000, from SP1 to SP4 and so on. AS these Update versions of the major package versions contain some differences, it is best not to mix, otherwise it is easy to cause problems. The installation packages for Prima and Plesk are designed specifically for various distributions on the download page and are usually identified as which versions and which update systems are supported.

ES is a stripped-down version of AS. The difference between him and the common AS series is that AS supports more than 4-way CPU, while ES can only support two-way CPU. There is no difference between AS and ES in most packages, only in a few packages such as the kernel. The price of AS is quite different from that of ES, and ES is usually used in the version of OEM purchased with the server. For example, if you buy a DELL server, the matching Linux will be the ES series. If you want to match the AS series, it will cost thousands more.

WS, which is a further simplified version of ES, is mainly aimed at the desktop office market within the enterprise, and is rarely used in China.)

Both Fedora Core Linux and Enterprise Linux of Redhat need to follow the GNU protocol, that is, they need to publish their own source code. So, for free Fedora Core Linux, you can download the ISO engraving directly from the Redhat website, and you can also download it to SRPM's ISO, the package source CD. For the paid Enterprise Linux series, it is a commercial product, so the ISO file cannot be downloaded on the website, so you need to purchase a formal license. Because Enterprise Linux also needs to follow the GNU protocol, the source code must be released. So on the Redhat website, you can get the SRPM source ISO files of the AS/ES/WS series. These files can be freely downloaded, modified, and recompiled.

Community Enterprise Operating System's project was born, and its abbreviation is both CentOS. The CentOS community downloads all the source code on Redhat's website and recompiles it. After recompilation, since AS/ES/WS is a commercial product, you must change the Logo and logo of all Redhat to your own CentOS logo. For example, after compiling the original SRPM source code of AS4, it becomes CentOS 4.0. When the source code of AS4Update1 is compiled, it becomes CentOS4.1. When the source code of AS4Update2 is compiled, it becomes CentOS4.2. Similarly, the 3.x/4.x of CentOS corresponds to the corresponding version.

So we say that CentOS is the free version of Redhat's AS/ES/WS. With CentOS, you can get the same performance and feel as AS/ES. In addition to several standard ISO numbered 1-4 or 1-5, CentOS also provides Server discs that minimize 1CD. A system installed with a Server CD is a minimized Linux kernel plus a commonly used httpd/MySQL package, excluding software such as Xwindows desktops that are useless to the server.

So in the future, if you look for centos's rpm package, you can find the corresponding Red Hat package.

Thank you for reading this article carefully. I hope the article "what's the difference between Centos and Redhat" shared by the editor will be helpful to you. At the same time, I also hope you will support us and pay attention to the industry information channel. More related knowledge is waiting for you to learn!

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