This document covers the following topics regarding Oracle Linux 6.
For the latest updates please refer to the online version of release notes available at:
NOTE: An upgrade of Oracle Linux from a beta release is not supported.
Further, an in-place upgrade between major versions of Oracle Linux is not supported. Oracle does not recommend an upgrade from earlier major versions of Oracle Linux even though anaconda provides an option to do this upgrade. A fresh installation is strongly recommended rather than a system upgrade between major versions.
Customers who want to use new features in Unbreakable Enterprise Kernel can do so without upgrading to Oracle Linux 6 as Oracle Linux 5.8 already includes Unbreakable Enterprise Kernel.
The following packages are modified from the upstream release. All changes are trademark and look/feel related unless otherwise noted below under the specific package.
The following packages have been removed.
The following packages have been added to the base release
Note: By default, both the Unbreakable Enterprise Kernel and the Red Hat Compatible Kernel for the specific architecture (i386 or x86_64) are installed, and the system boots the Unbreakable Enterprise Kernel by default. If needed, /etc/grub.conf and /etc/sysconfig/kernel can be modified to make the system boot with the Red Hat Compatible Kernel by default.
The Unbreakable Enterprise Kernel Release 2 is based on the upstream kernel 3.0.16 stable source tree.
This release of the Unbreakable Enterprise Kernel has been improved/enhanced by Oracle in several areas, including bug fixes and extended functionality. All of these modifications have been contributed back upstream and are available in mainline Linux.
Btrfs provides a flexible way to manage storage, without needing a separate volume manager. It provides built-in RAID support and ensures data integrity by using redundancy and checksums. Btrfs also supports lightweight copies/clones of files or directories with snapshots as well as online data compression. The Btrfs code in the Unbreakable Enterprise Kernel Release 2 includes many new features as well as numerous performance improvements, that were merged from a number of long running projects and cleanup queues.
Note: The standard installation media does not have support for creating a btrfs root filesystem on initial install. If you want to install Oracle Linux 6 Update 3 and use btrfs as your root filesystem, please use the alternative boot ISO media which uses btrfs as the default root filesystem. Using the boot.iso requires that the full installation source be available via a network method, i.e. FTP, HTTP or NFS.
New Btrfs features/functionality
Btrfs bug fixes and performance improvements
Several bug fixes and improvements have been incorporated to make the Unbreakable Enterprise Kernel scale and cooperate better as a guest (domU) in Oracle VM and Xen.
As Oracle Linux 6 Update 3 now ships with the latest Unbreakable Enterprise Kernel Release 2, upgrading via the installation media will evaluate whether or not to install this latest kernel based on the currently installed kernel.
The following upgrade scenarios should be considered:
If you have an existing Oracle Linux 6 GA, Update 1 or Update 2 install that does not have the already released Unbreakable Enterprise Kernel Release 2 installed, the Oracle Linux 6 Update 3 media will not install this kernel by default. Note that the Oracle Linux 6 Update 3 installation media does not contain any updates to the original Unbreakable Enterprise Kernel, so in this scenario, only the latest Red Hat Compatible Kernel will be installed.
If you have an existing Oracle Linux 6 GA, Update 1 or Update 2 install that already has the released Unbreakable Enterprise Kernel Release 2 installed, the Oracle Linux 6 Update 3 media will install the latest version of this kernel.
Upgrades that are performed via YUM will use whatever repositories are configured to upgrade the system. The latest Unbreakable Enterprise Kernel Release 2 can be found in the ol6_<arch>_UEK_latest repository, i.e. either ol6_i386_UEK_latest or ol6_x86_64_UEK_latest. You should ensure that this repository is enabled either via the Unbreakable Linux Network or in the /etc/yum.repos.d/public-yum-ol6.repo file if you want to install this kernel.
This can occur on Oracle VM 3.0 if the guest is set with a maximum memory (maxmem) parameter greater than the amount set at boot (memory). To avoid this issue, please ensure the maxmem and memory parameters are equal. This issue has been resolved in Oracle VM 3.1.1.
In certain cases, after successfully completing installation and rebooting the system, it is possible that the following error stack appears:Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python2.6/site-packages/meh/handler.py", line 161, in (lambda) File "/usr/lib/anaconda/exception.py", line 44, in handleException File "/usr/lib/python2.6/site-packages/meh/handler.py", line 106, in handleException File "/usr/lib/anaconda/gui.py", line 1169, in mainExceptionWindow ImportError: No module named ui.guiOr:14:05:55 CRITICAL: anaconda 18.104.22.168 exception report Traceback (most recent call first): File "/usr/lib64/python2.6/site-packages/gtk-2.0/gtk/_lazyutils.py", line 32, in __ getattr__ File "/usr/lib/anaconda/gui.py", line 1453, in keyRelease if ((event.keyval == gtk.keysyms.KP_Delete ImportError: No module named keysymsThese errors would also be logged in anaconda.log in /root after installation. These errors can safely be ignored.
The upstream release has added support for FCoE target service. This is not supported with the previous release of the Unbreakable Enterprise Kernel (2.6.32). Customers wishing to use this service must boot into the Unbreakable Enterprise Kernel Release 2 (2.6.39) or the Red Hat Compatible Kernel.
This service is not supported with the previous release of the Unbreakable Enterprise Kernel (2.6.32). Customers wishing to use this service must boot into the Unbreakable Enterprise Kernel Release 2 (2.6.39) or the Red Hat Compatible Kernel.
Both the new mlnx_en and ofa packages contain mlx4_core. Only one of the two packages should be installed. Attempts to install both packages on a single server will result in a package conflict error. To determine which package to use, if you have a Mellanox Ethernet Controller, please use mlnx_en. If you have a Mellanox Infiniband Controller, please use ofa. If you have both, please use ofa as it supports both Ethernet and Infiniband controllers.
When configuring the crash kernel for the UEK, only standard crash kernel settings, e.g. crashkernel=128M@32M, are supported. The new setting used by the RHCK, i.e. crashkernel=auto, is not supported and will cause the kdump service to fail to start.
To get rid of this error at boot time, add the line "blacklist iTCO_wdt" to /etc/modprobe.d/blacklist-watchdog
To get rid of this error at boot time, add the line "blacklist iTCO_wdt" to /etc/modprobe.d/blacklist-watchdog
The Unbreakable Enterprise Kernel adds support for paravirtualized drivers in a HVM guest on Oracle VM. The default is to present only paravirtualized drivers when running in a hardware virtualized guest. To run kernel-uek --including the drivers-- fully hardware virtualized, an additional kernel boot parameter "xen_emul_unplug=never" must be added to the boot parameters in /etc/grub.conf:kernel /vmlinuz-2.6.32-300.2.1.el6uek ro root=/dev/VolGroup00/LogVol00 xen_emul_unplug=neverAdding this kernel boot parameter makes the kernel also present the emulated drivers as it did before (e.g. the 8139cp network driver).
Selecting all packages in certain groups during installation might not show the correct count.
Oracle Linux 6 defaults to strict reverse path filtering. Some Oracle products and network storage devices work more reliably when using loose reverse path filtering. To enable loose mode reverse path filtering, issue the following command (assuming you are changing settings for the network interface called eth1). The default setting is 1.sysctl net.ipv4.conf.eth1.rp_filter=2
Certain network operations that utilize receive packet steering could cause errors on the system.
When failed paths are restored in a multipath configuration, you may see udevd-work error messages in /var/log/messages. The failed paths do get restored despite these messages.
The default NFS mount option has changed to NFS v4. To mount an NFS volume using NFS v3 (the default in Oracle Linux 5), use the following mount options:-o vers=3,mountproto=tcp
To set the serial console a hardware virtualized (HVM) guest use following settings in the guest:
- On the kernel boot line in grub.conf, add:console=tty0 console=ttyS0,57600n8
- add the following to /etc/securettyttyS0
If, during installation on an x86_64 system, the pam.i386 package is installed either manually or via package dependency, and the oracle-rdbms-server-11gR2-preinstall package is also selected, the Oracle Database related settings in /etc/security/limits.conf will be overwritten by the installation of the pam.i386 package. This is most likely to occur when using a kickstart-based automated installation that includes non-standard package selections. To restore these settings, run the oracle-rdbms-server-11gR2-preinstall-verify script.
After an install of Oracle Linux 6, the screens after the first reboot will guide you to register your system to the Unbreakable Linux Network (ULN). If you did not configure your network during the initial installation, the registration process to ULN will not succeed. In this case, you should configure your network by running NetworkManager first (as root). Then restart the ULN registration by running uln_register (as root).
On some hardware, the console may appear to hang during the boot process after starting udev. But the system does boot up properly and is accessible. A workaround to this problem is to add nomodeset as a kernel boot parameter in /etc/grub.conf:kernel /vmlinuz-2.6.32-300.2.1.el6uek.x86_64 ro root=/dev/sd0 nomodeset
For the Unbreakable Enterprise Kernel, the default IO scheduler is the 'deadline' scheduler.
For the Red Hat Compatible Kernel, the default IO scheduler is the 'cfq' scheduler.
For the Unbreakable Enterprise Kernel, kernel.sched_compat_yield=1 by default.
For the Red Hat Compatible Kernel, kernel.sched_compat_yield=0 by default.
The following Technology Preview features are currently not supported under Oracle Linux 6 and may not be functionally complete:
The following Technology Preview features are only available when running the Red Hat Compatible Kernel (RHCK):
These features are not suitable for production use. However, these features are included to provide the feature with wider exposure.
Oracle Linux 6 no longer contains up2date for access to Unbreakable Linux Network. Instead packages are managed using Yum. To register with ULN, use the following command:# uln_register
To access Linux updates via Unbreakable Linux Network, you must purchase a Linux support subscription. For more information please visit http://linux.oracle.com.
During ULN registration the server will be automatically registered with two channels: the latest channel for the base repository as well as the latest channel for the Unbreakable Enterprise Kernel Release 2. If you have upgraded from a previous release and do not wish the UEK Release 2 to be installed, you will need to manually unsubscribe the server from this channel.
The Unbreakable Linux Network includes Oracle-specific software packages, for example Oracle's ASMlib userspace package and the Oracle Instant Client. To enable access to these packages, login to the Unbreakable Linux Network and subscribe to the "Oracle Software" channel.
Oracle now provides all errata and updates for Oracle Linux via the public yum service. This service does not require a Linux support subscription, but only includes updates to the base distribution and does not include Oracle-specific software. To enable updates via public-yum, please visit http://public-yum.oracle.com and follow the instructions on that website.
By default, all new installs of Oracle Linux 6 Update 3 are automatically configured to use the public-yum update service. No modification is required to use this service. The public-yum service is automatically disabled when a server is registered with the Unbreakable Linux Network.
Note: Oracle Linux 6 Update 3 now contains two distinct repository sources on the installation media. To configure yum to use the installation media as a yum source, create the following file /etc/yum.repos.d/Media.repo with content similar to the following:
[ol6_base_media] name=Oracle Linux 6 Update 3 Base Media baseurl=file:///media/Server gpgcheck=0 enabled=1 [ol6_uek_media] name=Oracle Linux 6 Update 3 UEK Media baseurl=file:///media/UEK2 gpgcheck=0 enabled=1
You may need to adjust the baseurl parameter to match where you mount the ISO media on your server.