CentOS 6.6 Release Notes
Last updated: November 15, 2014
- Install Media and sha256sum
- Major changes
- Deprecated Features
- Known Issues
- Fixed 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 6.6 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 i386: 3d807eca07de83b0b24340b4dd41dc46cfd3802291d49608f088fd4c94c497f0 CentOS-6.6-i386-bin-DVD1.iso acb0ff01b3cfe7079877801b36d895a294443a98859d299310d12922c05b86fc CentOS-6.6-i386-bin-DVD2.iso a3e9d4e699193f61ad8703d1322676bad416f7e8b3f74cf62a1831cc45703190 CentOS-6.6-i386-minimal.iso 85a327acaa6e1ac7cbecd0b5f94f97808f3e31632e15f50c22377f6c6e9dcd46 CentOS-6.6-i386-netinstall.iso sha256sum x86_64: a63241b0f767afa1f9f7e59e6f0f00d6b8d19ed85936a7934222c03a92e61bf3 CentOS-6.6-x86_64-bin-DVD1.iso 89dac78769b26f8facf98ce85020a605b7601fec1946b0597e22ced5498b3597 CentOS-6.6-x86_64-bin-DVD2.iso 5458f357e8a55e3a866dd856896c7e0ac88e7f9220a3dd74c58a3b0acede8e4d CentOS-6.6-x86_64-minimal.iso ad8f6de098503174c7609d172679fa0dd276f4b669708933d9c4927bd3fe1017 CentOS-6.6-x86_64-netinstall.iso
ISO downloads are available here
4. Major changes
- Enhanced SCSI unit attention handling to enable responding to certain unit commands.
The OpenvSwitch module is now available as a kernel module.
- New HyperV daemons have been added to enable/improve running CentOS in Microsoft HyperV hosts.
- As a technology preview 6.6 can be run as a 2nd generation VM on Microsoft's 2012R2 HyperV.
- keepalived and haproxy are now fully supported.
- Support added for the Intel Wildcat platform.
- OpenJDK 8 has been added as technology preview.
5. Deprecated Features
The following packages were deprecated in CentOS 6.3 and have now been removed from CentOS 6.6:
The following packages have been deprecated and may get removed in future releases. They will no longer receive updates:
6. Known Issues
Note: The POODLE vulnerability is included in the openssl that is provided on the install media. Please run yum update after installation from any install media to get security updates for CentOS-6.6
The netinstall isos do not work with UEFI installs, but the minimal or DVD isos do work with UEFI. No versions of CentOS-6.6 will work with Secure Boot turned on. Secure Boot must be disabled to install CentOS-6.6. (For further detail please take a look at CentOS Bug #0006321).
- With this release the ABI for the X.org video drivers changes, possibly resulting in a failing X-Session. If you are running 3rd party drivers - i.e. vBox addons, nVidia, ATI or ELRepo - you need to ensure a compatible driver is loaded. In the case of vBox rebuilding the vBox-addons and restarting the X-Session solves this issue. This should not concern anyone who uses the default drivers shipped with CentOS.
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 #0005281 for details. Here are the SRPMS still affected in the 6.6:
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-6.6-x86_64-bin-DVD1.iso of=/dev/sdb
- The behaviour of IPA-installations change in two ways: When a password is expired and kinit prompts a new password a ticket no longer appears to be granted on change but rather a new kinit is needed with the new credentials. When installing the client side of IPA (this includes the automatic client part of installing the server side) sudo is now configured automatically and needs no modifiying of sssd.conf or nsswitch.conf.
7. Fixed Issues
8. Packages and Applications
8.1. Packages modified by CentOS
8.2. Packages removed from CentOS that are included upstream
8.3. Packages added by CentOS that are not included upstream
8.4. Packages released as 6.5 updates with older packages on the 6.6 install media
All CentOS sources are now hosted at vault.centos.org:
Software Collections: http://vault.centos.org/6.6/SCL/Source/SPackages/
10. 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.
10.1. 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
10.2. Mailinglists and Fora
10.3. 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.
11. 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/6.6_Release_Notes/index.html
Upstream technical notes : https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/6.6_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) 2014 The CentOS Project