CentOS (Community Enterprise Operating System) is a Linux distribution that provides a free, enterprise-class, community-supported computing platform functionally compatible with its upstream source, Red Hat Enterprise Linux (RHEL). In January 2014, CentOS announced the official joining with Red Hat while staying independent from RHEL, under a new CentOS governing board.
In June 2006, David Parsley, the primary developer of Tao Linux (another RHEL clone), announced the retirement of Tao Linux and its rolling into CentOS development. Tao’s users migrated to the CentOS release via yum update.
In July 2009, it was reported in an open letter on the CentOS project web site 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.
In July 2010, CentOS overtook Debian to become the most popular Linux distribution for web servers, with almost 30% of all Linux web servers using it. Debian retook the lead in January 2012.
In January 2014, Red Hat announced that it would sponsor the CentOS project, “helping to establish a platform well-suited to the needs of open source developers that integrate technologies in and around the operating system”. As a result of these changes, ownership of CentOS trademarks was transferred to Red Hat, which now employs most of the CentOS head developers; however, they work as part of Red Hat’s Open Source and Standards team, which operates separately from the Red Hat Enterprise Linux team.
CentOS 7 arrived almost exactly one month after RHEL 7. Previous major version updates have taken significantly longer, with the bump from version 5 to 6 taking eight months. Point releases are usually quicker, but this is the first time we’e seen CentOS track its parent distro’s release schedule so closely.
|Supports i386 Systems (32-bit Pentium, AMD)||Yes||Yes|
|Supports x86_64 systems (AMD64/EM64T)||Yes||Yes|
|Supports ia64 systems (Itanium2)||No||No|
|Supports s390/s390x systems (IBM zSeries & IBM S/390)||No||No|
|Supports PowerPC8le systems (IBM Power, Mac)||No||Yes|
|Supports ARMv7hl systems||No||Yes|
|Supports AArch64 (arm64) systems||No||Yes|
|CPU / Memory / Filesystem limits (Tested/possible)|
|Maximum logical CPUs|
|Maximum filesize (ext3)||2TB||2TB|
|Maximum file system size (ext3)||16TB||16TB|
|Maximum filesize (ext4)||16TB||16TB|
|Maximum file system size (ext4)||16TB/1EB||50TB/1EB|
|Maximum filesize (XFS)||100TB||500TB|
|Maximum file system size (XFS)||n/a||500TB|
|Maximum file system size (GFS2)||100TB||100TB|
|Maximum boot LUN size (BIOS)||2TB||2TB|
|Maximum boot LUN size (EFI)||Any||50TB|
|Maximum x86 per-process virtual address space||Approx 3GB|
|Maximum x86_64 per-process virtual address space||128TB||128TB|
|Recommended minimum requirements|
|other architectures||1G||1GB/logical CPU|
|Minimum/Recommended disk space||1G/5GB||10GB/20GB|
|Maximum number of cores on host||160|
|Maximum memory on host||2TB|
|Maximum number of vCPUs in fully virtualized guest (x86/x86_64)||160/160|
|Maximum memory in fully virtualized guest (x86/x86_64)||2TB/2TB|
|Minimum memory in fully virtualized guest (x86/x86_64)||512MB/512MB|
|OS features (Kernel, Server, Client, etc.)|
|Kernel foundation||Linux 2.6.32||Linux 3.10.0|
|Compiler/toolchain||GCC 4.4||GCC 4.8.5|
|Ext3 Performance Enhancements||Yes||Yes|
|Native POSIX Threading Library (NPTL)||Yes||Yes|
|IPv6 support||Ready Logo Phase 2||Ready Logo Phase 2|
|Logical Volume Manager (LVM)||Yes – LVM2||Yes – LVM2|
|Auditing||Yes – audit||Yes – audit|
|Compatibility libraries (toolchain)||Yes – CentOS 4 & CentOS 5||Yes – CentOS 5 & CentOS 6|
|LSB support||Yes – 4.0||Yes – 4.1|
|Web Server||httpd 2.2.15 (apache)||httpd 2.4.6 (apache)|
|Server Message Block (SMB)||Samba-3.5.x (opt. 4.0.x)||Samba-4.1.x|
|Database||MySQL 5.1.x, PostgreSQL 8.4.x||MariaDB 5.5.x, PostgreSQl 9.2.x|
|Programming Languages||php 5.3.3, python 2.6.6, perl 5.10.1||php 5.4, python 2.7, perl 5.16.3|
|Desktop GUI||X.org 7.4||Gnome 3.22, KDE 4.14|
|Graphics||Evolution 2.32 , Thunderbird 60||X.org 7.7|
|eMail Client||Firefox 60||Evolution 3.22, Thunderbird 60|
|Default browser||Libreoffice 220.127.116.11||Firefox 60|
|Office Suite||Yes (mp3 with add. repos)||Libreoffice 18.104.22.168|
|Multimedia capabilities||Yes||Yes (mp3 with add. repos)|
|Plug and Play||Yes||Yes|
According to the Red Hat Enterprise Linux (RHEL) life cycle, CentOS 5, 6 and 7 will be “maintained for up to 10 years” as it is based on RHEL. Previously, CentOS 4 had been supported for seven years.
|CentOS version||Release date||Full updates||Maintenance updates|
|3||19 March 2004||20 July 2006||31 October 2010|
|4||9 March 2005||31 March 2009||29 February 2012|
|5||12 April 2007||31 January 2014||31 March 2017|
|6||10 July 2011||10 May 2017||30 November 2020|
|7||7 July 2014||Q4 2020||30 June 2024|
About Software Licence
software license is an agreement between you and the owner of a software program that allows you to do certain things that would otherwise be an infringement of copyright law. The software license usually answers questions such as
- Where and how and how often can you install the program?
- Can you copy, modify, or redistribute it?
- Can you look at the underlying source code?
Software licence types
Proprietary is also known as “closed-source software” and non-free software. Proprietary software remains the property of its owner/creator and is used by end-users/organisations under predefined conditions and mainly used for commercial release.
Ex: Microsoft office, Microsoft Windows
Freeware is software, most often proprietary, usually small downloadable utilities. You don’t have the right to view the source code, and you do not have right to copy and redistribute the software. It mainly comes bundled with any operating system or you can download it from internet.
Ex: Adobe Reader, Free Studio, Skype, Internet Explorer etc.
Shareware (also known as trial ware or demoware) — Trial software that you can use free of charge for a limited time (usually 30 or 60 days). After that, when the trial period ends, the software must be purchased or uninstall.
Open source is software it’s source code is freely available to use, modify and redistribute. This software comes under GPL(General Public Licence)
Ex: GNU/Linux, Mozilla Firefox, VLC, VNC, Libre office etc.
What does GNOME mean?
GNOME (pronounced gah-NOHM) is a free and open source desktop environment and graphical user interface that runs on top of UNIX-based operating system.
What does GNU mean?
GNU (pronounced guh-noo) is a Unix-like computer operating system developed by the GNU project, Free Software Foundation. GNU operating system composed entirely of free software, ultimately aiming to be a complete Unix-compatible software system composed wholly of free software. GNU is a recursive acronym for “GNU’s Not Unix”, chosen because GNU’s design is Unix-like, but differs from Unix by being free software and containing no Unix code.