CentOS 6.8 Release Notes

CentOS 6.8 Release Notes

Last updated: May 30, 2016

Contents

Translations
Introduction
Install Media and sha256sum
Major changes
Deprecated Features
Known Issues
Packages and Applications
Packages modified by CentOS
Packages removed from CentOS that are included upstream
Packages added by CentOS that are not included upstream
Sources
How to help and get help
Special Interest Groups
Mailinglists and Fora
Wiki and Website
Further Reading
Thanks
1. Translations

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




English (en)








简体中文 (zh-cn) - Timothy Lee
繁體中文 (zh-tw) - Timothy Lee

2. Introduction


Welcome to the CentOS 6.8 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 (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.

NOTE: There is NO mechanism to pick only partial upgrades of packages to CentOS-6.8. All packages and updates to the 6.8 tree are built against the 6.8 tree and may not work correctly with older 6.x packages. If you want some packages in 6.8, please upgrade all packages. You will have issues if you perform only partial updates.

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:
1dda55622614a8b43b448a72f87d6cb7f79de1eff49ee8c5881a7d9db28d4e35  CentOS-6.8-x86_64-bin-DVD1.iso
0aba869427b4ce04e100d72744daf7fea1f7be2e4be56b658095bd9e99e04e6d  CentOS-6.8-x86_64-bin-DVD2.iso
efa82d673206cb6af377b1f929a510cc2b1ce95cdb436210121ec271e056c920  CentOS-6.8-x86_64-LiveCD.iso
52a9c8c1d250de39976dda9412293473b8349efefb31b66fecdee0fdf93866d9  CentOS-6.8-x86_64-LiveDVD.iso
ec49c297d484b9da0787e5944edc38f7c70f21c0f6a60178d8e9a8926d1949f4  CentOS-6.8-x86_64-minimal.iso
56d9cc5757ed1443af7b321967622a108978328f72e58050d31bcf1998dfd162  CentOS-6.8-x86_64-netinstall.iso


sha256sum i386:
720d185fdf063383a4471657076b72fc162d3c3c3bca2e5e5ae13a25b3046519  CentOS-6.8-i386-bin-DVD1.iso
0c1a498a469214f276b4390a9ac2111fe8eb89084f7921d2eced659ada09e1a9  CentOS-6.8-i386-bin-DVD2.iso
7df6c27c0cd1186845bee4e786d43dbd3ae429258098283f9dbc2b2d20ed6a89  CentOS-6.8-i386-LiveCD.iso
7e2ace104901921ac919a390be827251727dfd04437fbd4e4d3024b6d70d8718  CentOS-6.8-i386-LiveDVD.iso
f4cf0614cc2ac451ffec5bd349ee74a1b31fd394e58561a07c38a21be5a4bdeb  CentOS-6.8-i386-minimal.iso
1668434d76e14a45a189b7810582e7e6ded686854f75b7f8ba053830a5706e57  CentOS-6.8-i386-netinstall.iso

ISO downloads are available here
4. Major changes

If you use the SCL or Xen4CentOS repositories the locations of these have changed as these repos are now being maintained by Special Interest Groups. If you get errors updating your SCLs, do: yum remove centos-release-SCL then yum install centos-release-scl-rh. Xen should update as part of the normal update process.
libreswan replaces openswan as VPN endpoint solution (support added in NetworkManager)
sssd has a number of new capabilities and now supports smart cards, support for SSLv2 has been disabled
XFS support increased to a maximum file system size of 300TB
various applications now support TLSv1.2, i.e. OpenLDAP, yum, stunnel, vsftpd, git, postfix and others. Also TLSv1.2 has been enabled by default in various packages
various applications now support elliptic-curve parameters, i.e. Perl Net:SSLeay or Perl IO::Socket::SSL
dmidecode now supports SMBIOS 3.0.0
kickstart files can now be pulled from https sources
chrony has been added as an alternative to NTPd
squid 3.4 is available as a replacement to squid 3.1
enhancements have been made for guests running Hyper-V i.e. reporting kernel crashes to the hypervisor or running as a generation 2 guest
New package rear can be used to continuously create recovery images
SSLv3 and older insecure protocols are disabled by default, and various packages now have more configuration options to select the desired protocols
libreoffice has been rebased to 4.3.7.2
various packages have been rebased to more current version i.e. elfutils, SystemTap, ipmitool, memtest86+, icedtea-web, various hardware drivers, shadow utils, virt-who and others
5. Deprecated Features

The following device drivers have been deprecated, they may be removed in future releases and will not receive updates:

3w-9xxx
3w-sas
3w-xxxx
aic7xxx
i2o
ips
megaraid_mbox
mptbase
mptctl
mptfc
mptlan
mptsas
mptscsih
mptspi
sym53c8xx
The following controllers from the megaraid_sas driver have been deprecated:

Dell PERC5, PCI ID 0x15
SAS1078R, PCI ID 0x60
SAS1078DE, PCI ID 0x7C
SAS1064R, PCI ID 0x411
VERDE_ZCR, PCI ID 0x413
SAS1078GEN2, PCI ID 0x78
The following controllers from the be2iscsi driver have been deprecated:

BE_DEVICE_ID1, PCI ID 0x212
OC_DEVICE_ID1, PCI ID 0x702
OC_DEVICE_ID2, PCI ID 0x703
NOTE: Deprecated drivers SHOULD still function in CentOS 6 until EOL, they will likely not be supported in future versions of CentOS (ie, CentOS 7)

The following packages have been deprecated and may be removed in future releases of CentOS 6. They will no longer receive updates:

python-qmf
python-qpid
qpid-cpp
qpid-qmf
qpid-tests
qpid-tools
ruby-qpid
saslwrapper
The following items have seen some or all items removed from the upstream source code:

openswan component
seabios component
Btrfs file system
eCryptfs file system
mingw component
virtio-win component
fence-agents component
systemtap component
matahari component
openscap component
Please see the Red Hat Technical Notes for more details concerning deprecated and removed functionality.

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.
UEFI on CentOS-6.8: None of the i386 (32 bit) CentOS-6.8 ISOs will work with UEFI. All the x86_64 CentOS-6.8 ISOs should boot and work with UEFI. No versions of CentOS 6 will work with Secure Boot turned on. Secure Boot must be disabled to install CentOS 6. (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/.ssh
ssh-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 6.8:
at-spi
gtk2-engines
libgail-gnome
There is an issue with loading the ipv6 kernel module in some cases, which produces this error: Unknown symbol unregister_inet6addr_notifier . See bug 10927 for details.
Due to the changes in the Xorg subsystem the VirtualBox Tools have to be rebuild for the GUI to start
If you use the SCL or Xen4CentOS repositories the locations of these have changed as these repos are now being maintained by Special Interest Groups. If you get errors updating your SCLs, do: yum remove centos-release-SCL then yum install centos-release-scl-rh. Xen should update as part of the normal update process.
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-6.8-x86_64-bin-DVD1.iso of=/dev/sdb
7. Packages and Applications

7.1. Packages modified by CentOS

abrt
anaconda
dhcp
esc
firefox
gnome-applets
gnome-desktop
httpd
initscripts
ipa
kabi-yum-plugins
kde-settings
kernel
libee
libreport
luci
ntp
openscap
openssl098e
plymouth
redhat-bookmarks
redhat-logos
redhat-lsb
redhat-rpm-config
sos
system-config-date
thunderbird
virt-p2v
xorg-x11-server
xulrunner
yum
zsh

7.2. Packages removed from CentOS that are included upstream

cc-eal4-config
libehca
libservicelog
lsvpd
libvpd
openssl-ibmca
powerpc-utils
ppc64-diag
ppc64-utils
python-rhsm
Red_Hat_Enterprise_Linux-Release_Notes*
redhat-access-insights
redhat-indexhtml
redhat-release-*
redhat-release-notes*
redhat-support-lib-python
redhat-support-tool
rhn-client-tools
rhnlib
rhn-setup
rhn-setup-gnome
rhnsd
rhnsdlibica
servicelog
s390utils
subscription-manager
subscription-manager-migration-data
virt-who
yaboot
yum-rhn-plugin

7.3. Packages added by CentOS that are not included upstream

centos-indexhtml
centos-release













8. Sources

All CentOS sources are now hosted at vault.centos.org:

CentOSPlus: http://vault.centos.org/6.8/centosplus/Source/SPackages/
Extras: http://vault.centos.org/6.8/extras/Source/SPackages/
OS: http://vault.centos.org/6.8/os/Source/SPackages/
Software Collections: http://vault.centos.org/6.8/SCL/Source/SPackages/
Updates: http://vault.centos.org/6.8/updates/Source/SPackages/
Xen4CentOS: http://vault.centos.org/6.8/xen4/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/6.8_Release_Notes/index.html
Upstream technical notes : https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/6.8_Technical_Notes/index.html
http://www.centos.org/
http://wiki.centos.org/
http://lists.centos.org/
CentOS-6 fora
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/
11. Thanks

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) 2016 The CentOS Project




- wong chee tat :)