CentOS
Encyclopedia
CentOS is a free
operating system
based on Red Hat Enterprise Linux
(RHEL). It exists to provide a free enterprise class computing platform and strives to maintain 100% binary compatibility with its upstream distribution. CentOS stands for Community ENTerprise Operating System.
CentOS is the most popular Linux distribution
for web servers with almost 30% of all Linux web servers using it.
for these packages is made public by Red Hat.
CentOS developers use Red Hat's source code to create a final product very similar to Red Hat Enterprise Linux. Red Hat's branding and logos are changed because Red Hat
does not allow them to be redistributed.
CentOS is available free of charge. Technical support is primarily provided by the community via official mailing lists, web forums, and chat rooms. The project is not affiliated with Red Hat and thus receives no financial or logistical support from the company; instead, the CentOS Project relies on donations from users and organizational sponsors.
Since mid-2006, starting with version 4.4 (formally known as Red Hat Enterprise Linux 4.0 update 4), Red Hat has adopted a versioning convention identical to that of CentOS, e.g., Red Hat Enterprise Linux 4.5.
The following architectures are not supported by CentOS (as of version 5):
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
based on Red Hat Enterprise Linux
Red Hat Enterprise Linux
Red Hat Enterprise Linux is a Linux-based operating system developed by Red Hat and targeted toward the commercial market. Red Hat Enterprise Linux is released in server versions for x86, x86-64, Itanium, PowerPC and IBM System z, and desktop versions for x86 and x86-64...
(RHEL). It exists to provide a free enterprise class computing platform and strives to maintain 100% binary compatibility with its upstream distribution. CentOS stands for Community ENTerprise Operating System.
CentOS is the most popular Linux distribution
Linux distribution
A Linux distribution is a member of the family of Unix-like operating systems built on top of the Linux kernel. Such distributions are operating systems including a large collection of software applications such as word processors, spreadsheets, media players, and database applications...
for web servers with almost 30% of all Linux web servers using it.
Structure
Red Hat Enterprise Linux is available only through a paid subscription service that provides access to software updates and varying levels of technical support. The product is largely composed of software packages distributed under either an open source or a free software license and the source codeSource code
In computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...
for these packages is made public by Red Hat.
CentOS developers use Red Hat's source code to create a final product very similar to Red Hat Enterprise Linux. Red Hat's branding and logos are changed because Red Hat
Red Hat
Red Hat, Inc. is an S&P 500 company in the free and open source software sector, and a major Linux distribution vendor. Founded in 1993, Red Hat has its corporate headquarters in Raleigh, North Carolina with satellite offices worldwide....
does not allow them to be redistributed.
CentOS is available free of charge. Technical support is primarily provided by the community via official mailing lists, web forums, and chat rooms. The project is not affiliated with Red Hat and thus receives no financial or logistical support from the company; instead, the CentOS Project relies on donations from users and organizational sponsors.
Versioning scheme
CentOS version numbers have two parts, a major version and a minor version. The major and minor version numbers respectively correspond to the major version and update set of Red Hat Enterprise Linux from which the source packages used to build CentOS are taken. For example, CentOS 4.4 is built from the source packages from Red Hat Enterprise Linux 4 update 4.Since mid-2006, starting with version 4.4 (formally known as Red Hat Enterprise Linux 4.0 update 4), Red Hat has adopted a versioning convention identical to that of CentOS, e.g., Red Hat Enterprise Linux 4.5.
Release history
The architecture information is taken from the CentOS Overview page.| CentOS Release | Architectures | RHEL base | CentOS release date | RHEL release date | Delay |
|---|---|---|---|---|---|
| 2 | i386 IA-32 IA-32 , also known as x86-32, i386 or x86, is the CISC instruction-set architecture of Intel's most commercially successful microprocessors, and was first implemented in the Intel 80386 as a 32-bit extension of x86 architecture... |
2.1 | 2004-05-14 | 2002-05-17 | 728d |
| 3.1 | i386, x86-64 X86-64 x86-64 is an extension of the x86 instruction set. It supports vastly larger virtual and physical address spaces than are possible on x86, thereby allowing programmers to conveniently work with much larger data sets. x86-64 also provides 64-bit general purpose registers and numerous other... , IA-64, s390, s390x |
3 | 2004-03-19 | 2003-10-23 | 148d |
| 3.3 | i386, x86-64, IA-64, s390, s390x | 3.3 | 2004-09-17 | 2004-09-03 | 14d |
| 3.4 | i386, x86-64, IA-64, s390, s390x | 3.4 | 2005-01-23 | 2004-12-12 | 42d |
| 3.5 | i386 | 3.5 | 2005-06-10 | 2005-05-18 | 23d |
| 3.6 | i386 | 3.6 | 2005-11-01 | 2005-09-28 | 34d |
| 3.7 | i386, x86-64, IA-64, s390, s390x | 3.7 | 2006-04-10 | 2006-03-17 | 23d |
| 3.8 | i386, x86-64 | 3.8 | 2006-08-25 | 2006-07-20 | 36d |
| 3.9 | i386, x86-64, IA-64, s390, s390x | 3.9 | 2007-07-26 | 2007-06-15 | 41d |
| 4 | i386, x86-64, various | 4 | 2005-03-09 | 2005-02-14 | 23d |
| 4.1 | i386, ia64, s390 | 4.1 | 2005-06-12 | 2005-06-08 | 4d |
| 4.2 | i386, x86_64, ia64, s390, s390x, alpha | 4.2 | 2005-10-13 | 2005-10-05 | 8d |
| 4.3 | i386, x86-64, ia64, s390, s390x | 4.3 | 2006-03-21 | 2006-03-12 | 9d |
| 4.4 | i386, x86-64 | 4.4 | 2006-08-30 | 2006-08-10 | 20d |
| 4.5 | i386, x86_64, IA-64 | 4.5 | 2007-05-17 | 2007-05-01 | 16d |
| 4.6 | i386, x86-64, IA-64, Alpha, s390, s390x, PowerPC (beta), SPARC (beta) | 4.6 | 2007-12-16 | 2007-11-16 | 30d |
| 4.7 | i386, x86-64 | 4.7 | 2008-09-13 | 2008-07-24 | 51d |
| 4.8 | i386, x86-64 | 4.8 | 2009-08-21 | 2009-05-18 | 95d |
| 4.9 | i386, x86-64 | 4.9 | 2011-03-02 | 2011-02-16 | 14d |
| 5 | i386, x86-64 | 5 | 2007-04-12 | 2007-03-14 | 28d |
| 5.1 | i386, x86-64 | 5.1 | 2007-12-02 | 2007-11-07 | 25d |
| 5.2 | i386, x86-64 | 5.2 | 2008-06-24 | 2008-05-21 | 34d |
| 5.3 | i386, x86-64 | 5.3 | 2009-03-31 | 2009-01-20 | 69d |
| 5.4 | i386, x86-64 | 5.4 | 2009-10-21 | 2009-09-02 | 49d |
| 5.5 | i386, x86-64 | 5.5 | 2010-05-14 | 2010-03-31 | 44d |
| 5.6 | i386, x86-64 | 5.6 | 2011-04-08 | 2011-01-13 | 85d |
| 5.7 | i386, x86-64 | 5.7 | 2011-09-13 | 2011-07-21 | 54d |
| 6 | i386, x86-64 | 6 | 2011-07-10 | 2010-11-10 | 242d |
| 6.1 | i386, x86-64 | 6.1 | TBD | 2011-05-19 | ? |
| CentOS Release | Full Updates | Maintenance Updates |
|---|---|---|
| 3 | 2006-07-20 | 2010-10-31 |
| 4 | 2009-03-31 | 2012-02-29 |
| 5 | Q4 2011 | 2014-03-31 |
| 6 | Q4 2014 | 2017-11-30 |
| CentOS Release | Architectures | RHEL base | CentOS release date |
|---|---|---|---|
| 4.7 - Server | i386, x86-64 | 4.7 | 2008-10-17 |
| 5.1 - LiveCD | i386 | 5.1 | 2008-02-18 |
| 5.2 - LiveCD | i386 | 5.2 | 2008-07-17 |
| 5.3 - LiveCD | i386 | 5.3 | 2009-05-27 |
| 5.5 - LiveCD | i386, x86-64 | 5.5 | 2010-05-14 |
| 5.6 - LiveCD | i386, x86-64 | 5.6 | 2011-04-08 |
| 6.0 - LiveCD | i386, x86-64 | 6.0 | 2011-07-25 |
| 6.0 - LiveDVD | i386, x86-64 | 6.0 | 2011-07-27 |
| 6.0 - MinimalCD | i386, x86-64 | 6.0 | 2011-07-28 |
Architectures
CentOS supports only the x86 architectures:- x86IA-32IA-32 , also known as x86-32, i386 or x86, is the CISC instruction-set architecture of Intel's most commercially successful microprocessors, and was first implemented in the Intel 80386 as a 32-bit extension of x86 architecture...
(32-bit) - x86-64X86-64x86-64 is an extension of the x86 instruction set. It supports vastly larger virtual and physical address spaces than are possible on x86, thereby allowing programmers to conveniently work with much larger data sets. x86-64 also provides 64-bit general purpose registers and numerous other...
(AMD's AMD64 and Intel's EM64T, 64-bit)
The following architectures are not supported by CentOS (as of version 5):
- IA-64 (Intel ItaniumItaniumItanium is a family of 64-bit Intel microprocessors that implement the Intel Itanium architecture . Intel markets the processors for enterprise servers and high-performance computing systems...
architecture, 64-bit) (beta support since CentOS 3) - PowerPCPowerPCPowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
/32 (Apple MacintoshMacintoshThe Macintosh , or Mac, is a series of several lines of personal computers designed, developed, and marketed by Apple Inc. The first Macintosh was introduced by Apple's then-chairman Steve Jobs on January 24, 1984; it was the first commercially successful personal computer to feature a mouse and a...
and PowerMac running the G3 or G4 PowerPC processor) (beta support since CentOS 3) - IBMIBMInternational Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
MainframeMainframe computerMainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...
(eServerEServerIBM eServer was a family of computer servers from IBM Corporation.Announced in the year 2000, it combined the various IBM server brands under one brand.The various sub-brands were at the same time rebranded from:...
zSeriesZSeriesIBM System z, or earlier IBM eServer zSeries, is a brand name designated by IBM to all its mainframe computers.In 2000, IBM rebranded the existing System/390 to IBM eServer zSeries with the e depicted in IBM's red trademarked symbol, but because no specific machine names were changed for...
and S/390) (not CentOS 5) - AlphaDEC AlphaAlpha, originally known as Alpha AXP, is a 64-bit reduced instruction set computer instruction set architecture developed by Digital Equipment Corporation , designed to replace the 32-bit VAX complex instruction set computer ISA and its implementations. Alpha was implemented in microprocessors...
(CentOS 4 only) - SPARCSPARCSPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....
(beta support since CentOS 3)
Bootable media version
- A Live CDLive CDA live CD, live DVD, or live disc is a CD or DVD containing a bootable computer operating system. Live CDs are unique in that they have the ability to run a complete, modern operating system on a computer lacking mutable secondary storage, such as a hard disk drive...
version of CentOS is available at mirror.centos.org. - A Live USBLive USBA live USB is a USB flash drive or a USB external hard disk drive containing a full operating system that can be booted. Live USBs are closely related to live CDs, but sometimes have the ability to persistently save settings and permanently install software packages back onto the USB device...
of CentOS can be created manually or with UNetbootinUNetbootinUNetbootin is a cross-platform utility that can create live USB systems and can load a variety of system utilities or install various Linux distributions and other operating systems without a CD.- USB Install :...
.
Tao Linux
Tao Linux was another prominent distribution derived from Red Hat Enterprise Linux. Its primary developer announced in June 2006 that Tao would be retired and rolled into CentOS development. Tao users migrated to the CentOS release via "yum update".History and organizational difficulties
In July 2009, it was reported that CentOS's founder, Lance Davis, had disappeared in 2008. Davis had ceased contribution to the project but continued to hold the registration for the CentOS domain and PayPal account. In August 2009, the CentOS team reportedly made contact with Davis and obtained the centos.info and centos.org domains.See also
- GNUGNUGNU is a Unix-like computer operating system developed by the GNU project, ultimately aiming to be a "complete Unix-compatible software system"...
, LinuxLinuxLinux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds... - List of Linux distributions
- FedoraFedora (operating system)Fedora is a RPM-based, general purpose collection of software, including an operating system based on the Linux kernel, developed by the community-supported Fedora Project and sponsored by Red Hat...
, community-supported Project, sponsored by Red HatRed HatRed Hat, Inc. is an S&P 500 company in the free and open source software sector, and a major Linux distribution vendor. Founded in 1993, Red Hat has its corporate headquarters in Raleigh, North Carolina with satellite offices worldwide.... - Red Hat Enterprise LinuxRed Hat Enterprise LinuxRed Hat Enterprise Linux is a Linux-based operating system developed by Red Hat and targeted toward the commercial market. Red Hat Enterprise Linux is released in server versions for x86, x86-64, Itanium, PowerPC and IBM System z, and desktop versions for x86 and x86-64...
, the commercial distribution on which CentOS is based - Scientific LinuxScientific LinuxScientific Linux is a Linux distribution produced by Fermi National Accelerator Laboratory and the European Organization for Nuclear Research...
, another distribution based on Red Hat Enterprise Linux which has RHEL6 clone - Oracle Linux, another distribution based on Red Hat Enterprise Linux which has RHEL6 clone
- Red Hat LinuxRed Hat LinuxRed Hat Linux, assembled by the company Red Hat, was a popular Linux based operating system until its discontinuation in 2004.Red Hat Linux 1.0 was released on November 3, 1994...