CentOS 6.0 Release Notes

Last updated: July 19th, 2011

1. Translations

Translations of these release notes are available for the following languages :

• Česky (cs) - David Hrbáč

• English (en)

• Español (es) - Alejandro_Feijóo

• 日本語 (ja) - Tadashi Jokagi

• Deutsch (de) - Marcus Moeller

• Português do Brasil (pt-br) - Cleber Paiva de Souza, Lucas do Amaral Saboya

• Romana (ro) - Manuel Wolfshant

• 简体中文 (zh-cn) - Timothy Lee

• 繁體中文 (zh-tw) - Timothy Lee

2. Introduction

Welcome to the CentOS 6.0 release. CentOS is an Enterprise-class Linux Distribution derived from sources freely provided to the public by our Upstream OS Provider (UOP)¹.

CentOS conforms fully with the upstream vendor's redistribution policy and aims to be 100% binary compatible. (CentOS mainly changes packages to remove upstream vendor branding and artwork.)

CentOS 6.0 represents many changes from previous releases.

CentOS 6.0 has been completely rebuilt using a newer build system and library checks to confirm upstream binary compatibility.

We have decided not to follow the UOP's usage of Installation Codes. All 'channels' are available to the System Administrator at time of installation.

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 or CentOS 4) 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.

Please read through the other sections before trying an install or reporting an issue.

3. Install Media and sha1sum

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i386 media and their sha1sums are:

fcf49e875cd4494f2af68cf257ab9e93523c9427  CentOS-6.0-i386-bin-DVD.iso
862815623d2e7990207dd78a281837c7eb719e83  CentOS-6.0-i386-netinstall.iso

--------------------------------------------
x86_64 media and their sha1sums are:

9de87b0c696ebd72b952edb4cc06c24cbdc37d81  CentOS-6.0-x86_64-bin-DVD1.iso
5e3834621f11fbcca78cf7d70625c647045f45f5  CentOS-6.0-x86_64-bin-DVD2.iso
23f9e606cbcbd52d2e5df3716a85cdde336f7bfe  CentOS-6.0-x86_64-netinstall.iso

--------------------------------------------

4. Known Issues

• The installer needs at least 392MB of memory to work. Text mode will automatically be used if the system has less than 652MB 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.

• The message "Insufficient memory to configure kdump!" appears during install. This is a known upstream bug which appears on systems with less than 4 GB RAM and solved by updating to kexec-tools-2_0_0-153_el6 or newer.

• Content for x86_64 is split into two DVDs. The second disk contains only packages from upstream's "Optional" channel. Installs not requiring any of the packages from the "Optional" category should run using only DVD#1.
• The i386 DVD is just a bit too large to fit on normal single layer DVD+R media. It can be burnt succesfully on DVD-R or dual-layer media.

• 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/.ssh

  ssh-copy-id from CentOS 6 is aware of selinux contexts and the previous workaround is not needed.

• Bug #4964 reports a problem with crashes due to gnome-applets. The issue is reportedly related to the build-order of gnome-system-monitor and gnome-applets. A rebuilt version of gnome-applets is linked in the bug report as a work-around for this issue.

• Bug #4969 reports that the x86_64 DVD fails to automatically install when booting from a uEFI based system. The workaround, as documented in the bug, is:

  1) Insert your CentOS 6.0 installation DVD into DVD drive
  2) In the pre-boot phase of system startup press <F11> to enter UEFI Boot Manager
  3) Enter 'UEFI Boot Settings'
  4) Choose 'Add Boot Option'
  5) Point to 'BOOTX64.efi' file, whose exact path is /EFI/EFI/BOOT/BOOTX64.efi on the DVD
  6) Add Description (e.g. "CentOS 6.0") and optionally add Optional Data (which is passed to the boot image, not necessary)

  After committing you should see that a new boot option has appeared in the UEFI Boot Manager. Choose this new option and enjoy your CentOS 6.0 installation!

5. Packages and Applications

5.1. Packages modified by CentOS

• abrt
• anaconda
• firefox
• httpd
• kabi-whitelists
• luci
• openssl098
• plymouth
• report
• xulrunner
• yum

5.2. Packages removed from CentOS that are included upstream

• abrt-plugin-bugzilla
• redhat-release-*
• redhat-release-notes*
• rhnlib
• rhn-check
• rhn-client-tools
• rhnsd
• rhn-setup
• rhn-setup-gnome
• yum-rhn-plugin

5.3. Packages added by CentOS that are not included upstream

• centos-release

6. 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.

6.1. 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

6.2. 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 mailinglists and the fora.

6.3. 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 mailinglist.

7. Further Reading

The following websites contain large amounts of information to help people with their CentOS systems :

• Upstream release notes and documentation : http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/index.html

• http://www.centos.org/

• http://wiki.centos.org/

• http://lists.centos.org/

• http://bugs.centos.org/

• http://planet.centos.org/

• http://mirrors.kernel.org/redhat/redhat/linux/enterprise/6Client/en/os/SRPMS/

• http://mirrors.kernel.org/redhat/redhat/linux/enterprise/6Server/en/os/SRPMS/

8. Thanks

We thank everyone involved for helping us produce this product.

Copyright (C) 2011 The CentOS Project

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