Hello and welcome to the third CentOS-7 release. The CentOS Linux distribution is a stable, predictable, manageable and reproducible platform derived from the sources of Red Hat Enterprise Linux (RHEL)1.
ISOs are also available via Torrent.
If the above is not for you, alternative downloads might be.
CentOS conforms fully with Red Hat’s redistribution policy and aims to have full functional compatibility with the upstream product. CentOS mainly changes packages to remove Red Hat’s branding and artwork.
We have decided not to follow Red Hat’s usage of Installation Roles. In CentOS Linux all content from every distribution ‘channel’ is made available to the user at time of installation.
The continuous release (CR) repository makes generally available packages that will appear in the next point release of CentOS, on a testing and hotfix basis until formally released. Please read through the other sections before trying an install or reporting an issue.
3. Install Media
Various installation images are available for installing CentOS. Which image you need to download depends on your installation environment. All of these images can either be burned on a DVD or dd’ed to an USB memory stick.
If you are unsure which image to use, pick the DVD image. It allows selecting which components you want to install.
Live media images are also available, both for Gnome and KDE desktop environments. These allow you to test out CentOS by booting from the DVD or USB stick. The third livecd image uses Gnome, and as the livecd name implies, it is small enough to fit on a CD. This image does not contain libreoffice. You can also install CentOS to your hard disk from the live media images, but please note that what gets installed on your hard disk is exactly the same as you see when using the live media. For more flexibility in selecting which packages you want to have installed, please use the DVD image.
The netinstall image can be used for doing installs over network. After booting the computer with the netinstall image, the installer will ask from where it should fetch the packages to be installed.
The everything image contains all the packages that are available for CentOS-7, including those that are not directly installable from the installer. If you want to install those other packages, you must mount the install media on your installed system after the installation, and copy or install the packages from there. For most users installing from the DVD image and then installing the other packages with ”yum install <packagename>” instead is probably easier.
At least 1024 MB RAM is required to install and use CentOS-7 (1511). When using the Live ISOs for install, 1024 MB RAM produces very slow results and even some install failures. At least 1280 MB RAM is recommended for LiveCD installs and at least 1344 MB RAM is recommend for LiveGNOME or LiveKDE installs.
4. Verifying Downloaded Installation Images
Before copying the image to your preferred installation media you should check the sha256sum of the downloaded installation images.
5. Major Changes
This section is to be reviewed:
Since release 1503 (abrt>= 2.1.11-19.el7.centos.0.1) CentOS-7 can report bugs directly to bugs.centos.org. You can find information about that feature at this page
- sudo is now capable of verifying command checksums
- A Kerberos https proxy is now available for identity management
NSS no longer accepts DH key parameters < 768 nor RSA/DSA certificates with key sizes < 1024 bits, NSS also now enables TLS1.1/1.2 by default
- various packages now support TLS1.1/1.2 and EC ciphers
- The maximum number of SCSI LUNs has been increased
- The virt-v2v command line tool is now fully supported
- dd can now show transfer progress
- OpenJDK7 now supports ECC for TLS connections
- TPM version 2.0 driver level support has been added
- tcpdump now supports nanosecond timestamps
- Various updates to the networking stack (i.e. VXLANs, Data Center TCP, TCP/IP Stack, IPSec, …)
- Various atomic related packages have been updated
- Update to the libATA, FCoE and DCB storage drivers
- Updates to various storage, network and graphics drivers
- Anaconda now supports NFS when adding additional repos during install
- Major rebases for the following: Gnome from 3.8 to 3.14, KDE from 4.3 to 4.14, Xorg-X11-Server from 1.15 to 1.17, libreoffice from 4.2.8 to 4.3.7. openldap from 2.4.39 to 2.4.40 and more.
Because of these rebases some 3rd party repositories (Like EPEL, ELRepo, nux!, etc.) may not have all their packages rebuilt to use the newer packages in this release. This may cause the inability to update to the new release until those repositories fix their dependencies. You should contact the 3rd party repository owner to get problems fixed, or remove problem packages from 3rd party repositories to complete the update to this release.
- Technology Preview: Support of the Btrfs file system, OverlayFS, DNSSEC, kpatch, virt-p2v tool and the Cisco VIC kernel driver
More information can be found at https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/7.2_Release_Notes/index.html.
6. Deprecated Features
There are no deprecated features in this release.
7. Known Issues
A list of known upstream issues can be found here. Given that we build from the same sources, many if not all of those issues will likely also apply to CentOS Linux.
- The initramfs files are now significantly bigger than in CentOS-7 (1503). You may want to consider lowering installonly_limit in /etc/yum.conf to reduce the number of installed kernels if your /boot partition is smaller than 4GB. New installations should consider using 1GB as the size of the /boot partition.
The updated libreoffice calc packages fix the bug which got introduced in CentOS-7 (1503) which affected sorting in spreadsheets. See this and this bug report.
- The newer version of openssh in this release does not exit on the first match in the .ssh/config file as the older version did. This means if you have multiple host sections that match in your config for a given host, ALL will be applied. As an example, if you have a “host1.example.com” entry and a “*.example.com” entry, it will apply BOTH sets of instructions to “host1.example.com” but only the “*.example.com” section for “host2.example.com”.
Many people have complained that Ethernet interfaces are not started with the new default NetworkManager tool/have to be explicitly enabled during installation. See CentOS-7 FAQ#2.
- At least 1024 MB RAM is required to install and use CentOS-7 (1511). When using the Live ISOs for install, 1024 MB RAM produces very slow results and even some install failures. At least 1344 MB RAM is recommend for LiveGNOME or LiveKDE installs.
- If your screen resolution is 800×600 or lower, parts of the images shown at the bottom during install are clipped.
VMware Workstation/VMware ESXi allow to install two different virtual SCSI adapters: BusLogic and LsiLogic. However the default kernel from CentOS-7 does not include the corresponding driver for any of them thus resulting in an unbootable system if you install on a SCSI disk using the defaults for CentOS Linux. If you select ‘Red Hat Enterprise Linux’ as OS, the paravirtualized SCSI adapter is used, which works.
Commonly used utilities such as ifconfig/netstat have been marked as deprecated for some considerable time and the ‘net-tools’ package is no longer part of the @core group so will not be installed by default. Use nmcli c up ifname <interfacename> to get your network up and running and use yum to install the package if you really need it. Kickstart users can pull in the net-tools package as part of the install.
The AlpsPS/2 ‘ALPS DualPoint TouchPad’ edge scrolling does not work by default on CentOS-7. See bug 7403 for the command to make this feature work.
In VirtualBox up to version 5.0.10 the building of the vBox additions fails. For more information look here. This is expected to be fixed in the next maintenance release of 5.0.
8. Fixed Issues
For all the fixed issues it is best to look at the errata release page here and look for fixes dated after November 19th 2015.
9. Packages and Applications
9.1. Packages modified by CentOS
This section is to be reviewed:
9.2. Packages removed from CentOS that are included upstream
9.3. Packages added by CentOS that are not included upstream
9.4. Packages released as 7 1.1503 updates with older packages on the 7.2.1511 install media
All CentOS-7 sources are hosted at git.centos.org. All code released into the distribution originated from git.centos.org.
Source RPMs will also be published once the release is done, in the usual location at http://vault.centos.org/centos/7/
From a CentOS machine you can easily retrieve sources using the yumdownloader –source <packagename> command.
11. How to help and get help
As a CentOS user there are various ways you can help out with the CentOS community. Take a look at our Contribute page for further information on how to get involved.
11.1. Special Interest Groups
CentOS consists of different Special Interest Groups (SIGs) that bring together people with similar interests. The following SIGs already exist (among others):
Artwork – create and improve artwork for CentOS releases and promotion
Promotion – help promoting CentOS online or at events
Virtualization – unite people around virtualization in CentOS
And we encourage people to join any of these SIGs or start up a new SIG, e.g.
- ARM, PPC and i386 port – help with porting CentOS to other architectures
- Hardware compatibility – provide feedback about specific hardware
- RPM Packaging – contribute new useful RPM packages
- Translation – help translating the documentation, website and Wiki content
11.2. Mailing Lists and Fora
Another way you can help others in the community is by actively helping and resolving problems that users come up against in the mailing lists and the fora.
11.3. Wiki and Website
Even as an inexperienced CentOS user we can use your help. Because we like to know what problems you encountered, if you had problems finding specific information, how you would improve documentation so it becomes more accessible. This kind of feedback is as valuable to others as it would have been to you so your involvement is required to make CentOS better.
So if you want to help out and improve our documentation and Wiki, register on the Wiki or subscribe to the centos-docs mailing list.
12. Further Reading
The following websites contain large amounts of information to help people with their CentOS systems:
Upstream release notes and documentation : https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/
We thank everyone involved for helping us produce this product and would like to specifically acknowledge the extra effort made by the QA Team. Without them working lots and lots of hours in evenings, nights, weekends and holidays, we couldn’t have released this Release as fast as we did. A special thanks also goes to the CentOS-community. A more complete list of the contributors to this release can be found at /usr/share/doc/centos-release/Contributors of your new CentOS-7 installation.
Copyright (C) 2015 The CentOS Project
- 1 Visit http://www.redhat.com/rhel/