Oracle Linux 6.2 Release Notes

Updated December 2011

Introduction

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:

http://oss.oracle.com/ol6/docs/

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 5.6 already includes Unbreakable Enterprise Kernel.

Packages added by the Upstream Release

The following packages have been added to the upstream release:

Changes from the Upstream Release

Packages modified from upstream release

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.

Packages removed from upstream release

The following packages have been removed.

New Packages added by Oracle

The following packages have been added to the base release

Kernel

Oracle Linux 6 ships with two sets of kernel packages:

Note:Oracle Linux 6.2 includes both a 32 bit and a 64 bit Unbreakable Enterprise Kernel. By default, both the Unbreakable Enterprise Kernel and the Red Hat Compatible Kernel are installed, and the system boots the Unbreakable Enterprise Kernel by default. If needed, /etc/grub.conf can be modified to make the system boot with the Red Hat Compatible Kernel by default.

Unbreakable Enterprise Kernel

The Unbreakable Enterprise Kernel is based on the upstream kernel 2.6.32-46 stable source tree with additional performance improvements, including:

Oracle Linux 6.2 includes both a 32 bit and a 64 bit Unbreakable Enterprise Kernel. The Unbreakable Enterprise Kernel is the default kernel after installation.

Unbreakable Enterprise Kernel Driver Updates from Update 1

Network Drivers updates

Storage Drivers updates

Other

Features

Known Issues

  1. Hardware virtualized with Paravirtualized Drivers (PVHVM) guests crash during Oracle Database install
  2. This can occur 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.
  3. Post-install Anaconda Errors
  4. 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.gui
    Or:
    14:05:55 CRITICAL: anaconda 11.5.0.47 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 keysyms
    These errors would also be logged in anaconda.log in /root after installation. These errors can safely be ignored.
  5. Cannot start FCoE Target service with Unbreakable Enterprise Kernel
  6. The upstream release has added support for FCoE target service. This is not supported with the current release of the Unbreakable Enterprise Kernel (2.6.32-300.3.1). Customers wishing to use this service must boot into the Red Hat Compatible Kernel. Support for this service will be included in a future release of the Unbreakable Enterprise Kernel.
  7. Cannot start CGroups Config service with Unbreakable Enterprise Kernel
  8. This service is not supported with the current release of the Unbreakable Enterprise Kernel (2.6.32-300.3.1). Customers wishing to use this service must boot into the Red Hat Compatible Kernel. Support for this service will be included in a future release of the Unbreakable Enterprise Kernel.
  9. mlx4_core conflicts between mlnx_en and ofa packages
  10. 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.
  11. kdump service fails to start with Unbreakable Enterprise Kernel
  12. When configuring the crash kernel for the UEK, only standard crash kernel settings, e.g. crashkernel=128@64M, 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.

    In some scenerios of kickstart install crashkernel=auto is set in kernel entry in /boot/grub/grub.conf file. Please change this setting as suggested above.
  13. "iTCO_wdt: failed to reset NO_REBOOT flag, reboot disabled by hardware" error in dmesg when running the Unbreakable Enterprise Kernel
  14. To get rid of this error at boot time, add the line "blacklist iTCO_wdt" to /etc/modprobe.d/blacklist-watchdog
  15. Hardware virtualized (HVM) guests with Unbreakable Enterprise Kernel always use paravirtualized (PV) drivers
  16. 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-2.6.32-300.3.1.el6uek ro root=/dev/VolGroup00/LogVol00  xen_emul_unplug=never
    
    Adding this kernel boot parameter makes the kernel also present the emulated drivers as it did before (e.g. the 8139cp network driver).

  17. Incorrect package count (11684244)
  18. Selecting all packages in certain groups during installation might not show the correct count.
  19. Default reverse path filtering mode affects certain Oracle products (10649976)
  20. 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 
    
  21. Spurious udev messages during restore of a failed path (11682171)
  22. 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.
  23. Default NFS v4 mount options
  24. 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
    
  25. Setting serial console in a hardware virtualized (HVM) guest
  26. To set the serial console a hardware virtualized (HVM) guest use following settings in the guest:
  27. Unbreakable Linux Network
  28. 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).
  29. Console appears to hang while booting on certain systems (10094052)
  30. 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-2.6.32-300.3.1.el6uek.x86_64 ro root=/dev/sd0 nomodeset
    
  31. Default IO scheduler
  32. 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.
  33. sched_yield() settings for CFS
  34. 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.
  35. Warning message when kdump starts
  36. When kdump starts, you may see the following warning message:
        WARNING: No modules scsi_mod found for kernel 2.6.32-300.3.1.el6uek.x86_64, continuing anyway
    
    This warning can be ignored. The kdump service does get started and a vmcore does get generated.
  37. Upgrading x86_64 system
  38. Please remove following packages if installed before upgarding x86_64 system to Oracle Linux 6 Update 2
  39. Installing xguest package
  40. Enable selinux (selinux=enforcing) before installing xguest package. xguest package installation will fail on a system with selinux disabled with following error:
            Running Transaction
             Error in PREIN scriptlet in rpm package xguest-1.0.9-2.el6.noarch
             error: %pre(xguest-1.0.9-2.el6.noarch) scriptlet failed, exit status 1
             error:   install: %pre scriptlet failed (2), skipping xguest-1.0.9-2.el6
    
  41. Ignorable message in the kernel log files
  42. You may see a message similar to this one in the kernel log files:
                virbr0: starting userspace STP failed, starting kernel STP
    
    This message indicates that the kernel tried to start a Spanning Tree Protocol helper program that is not yet part of Oracle Linux. The message indicates that the kernel is using its own STP helper instead.
  43. Paravirtualized guest hang during save/restore or live migration (13492670)
  44. Paravirtualized guest may hang during save/restore or live migration when microcode module is loaded. Please remove the microcode module before save/restore or live migrate operation.
  45. Error inserting cxgb3i module (13493043)
  46. iscsi offload via cxgb3i on a server with Chelsio T3 Network Controller will fail with following error if ofa kernel package is installed
               fatal: error inserting cxgb3i - unknown symbol t3_l2e_free
    
    Use following workaround steps to fix the issue:

Technology Preview Features

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.

Unbreakable Linux Network

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