CentOS 6.7 Release Notes
Last updated: September 5, 2015
- Install Media and sha256sum
- Major changes
- Deprecated Features
- Known Issues
- Packages and Applications
- How to help and get help
- Further Reading
Translations of these release notes are available for the following languages :
Welcome to the CentOS 6.7 release. CentOS is an Enterprise-class Linux Distribution derived from sources freely provided to the public by Red Hat1.
CentOS conforms fully with Red Hat's redistribution policy and aims to be functionally compatible. CentOS mainly changes packages to remove upstream vendor branding and artwork.
Similar to the practice of the upstream vendor, there is no supported path to 'upgrade' an installation of a prior major CentOS release (presently CentOS 5) to a new major release. This is not a CentOS imposed limitation, but rather reflects the upstream's approach on this matter. People who feel adventuresome and want to experiment are reminded to take and test backups first. As a note to people who attempt the upgrade in spite of this warning, such as by the unsupported upgradeany option from the media install command line, please note that you will need to manually retrieve the current centos-release package, manually do a rpm -e --nodeps removal of the prior centos-release package, and then manually install the CentOS 6 centos-release package, before yum can have any chance of working properly.
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 and sha256sum
- The installation kit is split into two DVDs. It is possible to do a full install with only the first DVD. The second DVD contains only supplementary RPMs, which can be installed afterwards if needed. The installer does not ask for the second DVD during installation.
sha256sum x86_64: c0c1a05d3d74fb093c6232003da4b22b0680f59d3b2fa2cb7da736bc40b3f2c5 CentOS-6.7-x86_64-bin-DVD1.iso f973ac2453af9815d2db944f3c7383bb3061b6b0c12fb58dadf843e1cad67ab6 CentOS-6.7-x86_64-bin-DVD2.iso 9d3fec5897be6b3fed4d3dda80b8fa7bb62c616bbfd4bdcd27295ca9b764f498 CentOS-6.7-x86_64-minimal.iso 411da8c3f66839eef9ae47bf4515cc0b82f2a1dfc7b2d5bde2d203ca7e3220f3 CentOS-6.7-x86_64-netinstall.iso sha256sum i386: 2ef003dd0a0b7e810928da9508d5551d8d51943434d4eb634a783f1fc3cb0252 CentOS-6.7-i386-bin-DVD1.iso e767a67fe9f7b2c9d30ed6ac56623d5acb4b57246d46187f13bbf5fcf4fb1014 CentOS-6.7-i386-bin-DVD2.iso fc4bfb9f94668e4d0fa14b3108de1fdc8b6d2096a95e6c2b14f595f1bad57bbf CentOS-6.7-i386-minimal.iso a1a9d1c0ffc62416b37ea1ee5150d76278b823a44c6f4ab5e749ec7ce071e38d CentOS-6.7-i386-netinstall.iso
ISO downloads are available here
4. Major changes
- sssd has a number of new capabilities
- Support for udev rules to restrict removable media to be mounted read-only for security
- LVM caching is now fully supported
- New package clufter can be used for analyzing and transforming cluster configuration formats
- SSLv3 and older insecure protocols are disabled by default, and various packages now have more configuration options to select the desired protocols
- vim has been rebased to version 7.4, with improvements to undo and regular expressions
- libreoffice has been upgraded to 220.127.116.11
- The KVM hypervisor can now handle up to 240 virtual CPUs per virtual machine
- IPv6 IP sets are now allowed in firewall rules
- squid has been rebased to version 3.1.23 and now supports HTTP/1.1 POST and PUT responses with no message body
- mdadm has been rebased to version 3.3.2, improving support for RAID level migrations and automatic array rebuilding
- the package yum-plugin-downloadonly is now superseded by the main yum package, as the feature has been integrated
5. Deprecated Features
The following packages have been deprecated and may get removed in future releases. They will no longer receive updates:
6. Known Issues
- On UEFI-capable systems, CentOS 6.x writes its boot configuration to /boot/efi/EFI/redhat. This will cause problems for those who want to have CentOS and RHEL installed on the same system. This issue may remain unfixed for the lifetime of CentOS 6. CentOS 7 does not have this issue.
VirtualBox may have problems starting CentOS 6 VMs that were created in UEFI mode.
boost-1.41.0-27.el6 as included in CentOS 6.7 may have issues building certain packages. See upstream bug #1245805 for details. If this is a problem for you, we recommend using boost-1.41.0-25.el6.centos from CentOS 6.6 updates until this issue has been fixed.
The satyr package from EPEL (now removed because of conflict with RHEL 6.7) is newer than the version included in CentOS 6.7. The package from EPEL seems to work OK as well. We have not observed any negative impacts from this issue. If you have already installed satyr from EPEL and want to switch to the CentOS version, try yum downgrade satyr.
- The json-c package from EPEL is older than the version included in CentOS 6.7. If you have already installed json-c from EPEL, uninstall it before updating the system to 6.7 to avoid possible yum issues.
sssd-common is no longer multilib in CentOS 6.7. If you have the 32bit sssd-common installed on your x86_64 system, you will need to remove it with yum remove sssd-common.i686 prior to updating.
The netinstall isos do not work with UEFI installs, but the minimal or DVD isos do work with UEFI. No versions of CentOS-6.7 will work with Secure Boot turned on. Secure Boot must be disabled to install CentOS-6.7. (For further detail please take a look at CentOS Bug #6321).
On Intel and AMD based processor architectures, CentOS 6 requires PAE support for 32-bit x86 chips, following the upstream's requirement
- The installer needs at least 406MB of memory to work. Text mode will automatically be used if the system has less than 632MB of memory.
The text installer has limited capabilities compared to the GUI installer. Most notably there is no support for configuring partition layout, storage methods or package selection. Please refer to the official documentation for details. Here you can find some useful information on creating and using kickstart files which can be used to perform advanced configuring without the need for the GUI installer.
- The message "Insufficient memory to configure kdump!" appears during install. This is a known issue which appears on systems with less than 2 GB RAM. This can be ignored.
- Content for both the i386 and x86_64 architectures is split into two DVDs. We have tried to get all basic server and basic desktop installs only from DVD-1.
- Make sure that you setup correctly the selinux context of the public key if you transfer it to a CentOS 6 server with selinux enabled. Otherwise selinux might forbid access to the ~/.ssh/authorized_keys file and by matter of consequence key authentication will not work. In order to setup the correct context you can use:
restorecon -R -v /home/$ACCOUNT/.sshssh-copy-id from CentOS 6 is aware of selinux contexts and the previous workaround is not needed.
Many people have complained that Ethernet interfaces are not started with the new default NetworkManager tool. See CentOS-6 FAQ#2.
Several packages have .centos. in their name but are not modified packages, see CentOS Bug #5281 for details. Here are the SRPMS still affected in the 6.7:
tigervnc has .centos. in the package name because it was rebuilt against new dependencies. The package itself has not been changed. See CentOS Bug #7804.
One can do USB key installs by using dd to copy individual ISO files to a USB key using the device name (not the partition name). This will overwrite the entire USB key. Here is an example for the DVD1:
dd if=CentOS-6.7-x86_64-bin-DVD1.iso of=/dev/sdb
7. Packages and Applications
7.1. Packages modified by CentOS
7.2. Packages removed from CentOS that are included upstream
7.3. Packages added by CentOS that are not included upstream
7.4. Packages released as 6.6 updates with older packages on the 6.7 install media
All CentOS sources are now hosted at vault.centos.org:
Software Collections: http://vault.centos.org/6.7/SCL/Source/SPackages/
9. 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.
9.1. Special Interest Groups
CentOS consists of different Special Interest Groups (SIGs) that bring together people with similar interests. The following SIGs already exist:
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.
- Alpha, S390, Sparc and PPC 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
9.2. Mailinglists 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.
9.3. 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.
10. 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/6/html/6.7_Release_Notes/index.html
Upstream technical notes : https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/6.7_Technical_Notes/index.html
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 almost 24/7 we couldn't have released this as fast as we did.
Copyright (C) 2015 The CentOS Project
Visit http://www.redhat.com/rhel/ (1)