Oracle® Linux

Release Notes for Unbreakable Enterprise Kernel Release 2 Quarterly
Update 5

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   E48381-02

   September 2013

   Abstract

   This document contains information on Quarterly Update 5 to the
   Unbreakable Enterprise Kernel Release 2. This document may be
   updated after it is released. To check for updates to this
   document, and to view other Oracle documentation, refer to the
   Documentation section on the Oracle Technology Network (OTN) Web
   site:

   http://www.oracle.com/technology/documentation/

   This document is intended for users and administrators of Oracle
   Linux. It describes potential issues and the corresponding
   workarounds you may encounter while using the Unbreakable
   Enterprise Kernel Release 2 with Oracle Linux 5 and Oracle Linux

   6. Oracle recommends that you read this document before installing
   or upgrading the Unbreakable Enterprise Kernel Release 2.

   Document generated on: 2013-09-28 (revision: 1240)
     _______________________________________________________

Preface

   The Oracle Linux Unbreakable Enterprise Kernel Release Notes
   provides a summary of the new features, changes, and fixed and
   known issues in the Unbreakable Enterprise Kernel Release 2.

Audience

   This document is written for system administrators who want to use
   the Unbreakable Enterprise Kernel with Oracle Linux. It is assumed
   that readers have a general understanding of the Linux operating
   system.

Documentation Accessibility

   For information about Oracle's commitment to accessibility, visit
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Related Documents

   The latest version of this document and other documentation for
   this product are available at:

   http://www.oracle.com/technetwork/server-storage/linux/documentati
   on/index.html.

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Chapter 1. New Features and Changes

   The Unbreakable Enterprise Kernel Release 2 (UEK R2) is Oracle's
   second major release of its heavily tested and optimized operating
   system kernel for Oracle Linux 5 and Oracle Linux 6. See the
   initial Oracle Unbreakable Enterprise Kernel Release 2 Release
   Notes (https://oss.oracle.com/ol6/docs/RELEASE-NOTES-UEK2-en.html)
   for a detailed description of the differences between UEK R2 and
   the first version of the Unbreakable Enterprise Kernel.

   The 2.6.39-400.209.1 release is the fifth quarterly driver update
   release, which also includes bug and security fixes.
   Note

   The version number displayed by the kernel and on the RPM packages
   is 2.6.39. This was done to avoid potential breakage of certain
   low-level utilities of the Oracle Linux distribution (also known
   as the plumbing) that potentially cannot cope with the new 3.x
   version scheme. Regular Linux applications are usually neither
   aware of nor affected by Linux kernel version numbers.

1.1. Notable Changes


     * Xsigo virtual host adapter and network drivers to support
       Oracle SDN (Software Defined Network), previously known as
       Xsigo Fabric Accelerator.

     * LSI Fusion-MPT SAS 3.0 driver to support up to 12 Gb/s host
       controllers.

1.2. Xen Improvements

   Relative to quarterly update 4, several improvements have been
   incorporated into the Unbreakable Enterprise Kernel to support Xen
   usage:

     * Fixes for EDD, x2apic, XenBus, and PVHVM vCPU hotplug issues.

     * The indirect-descriptor feature, which increases throughput
       and reduces latency for block I/O.

1.3. Driver Updates

   The Unbreakable Enterprise Kernel supports a wide range of
   hardware and devices. In close cooperation with hardware and
   storage vendors, several device drivers have been updated by
   Oracle.

1.3.1. Storage Adapter Drivers

Adaptec


     * AACRAID driver (aacraid) updated to 1.2-0[30200]-ms.

Cisco


     * Cisco FCoE HBA Driver (fnic) updated to 1.5.0.45.

Emulex


     * Fibre Channel HBA driver (lpfc) updated to 0:8.3.7.26.3p.

Intel


     * C600 serial attached SCSI (SAS) module (isci) updated to
       1.0.0.

LSI


     * LSI Fusion-MPT base driver (mptbase) updated to 4.28.20.02.

     * LSI Fusion-MPT ioctl driver (mptctl) updated to 4.28.20.02.

     * LSI Fusion-MPT Fibre Channel host driver (mptfc) updated to
       4.28.20.02.

     * LSI Fusion-MPT IP Over Fibre Channel driver (mptlan) updated
       to 4.28.20.02.

     * LSI Fusion-MPT SAS driver (mptsas) updated to 4.28.20.02.

     * LSI Fusion-MPT SCSI host driver (mptscsih) updated to
       4.28.20.02.

     * LSI Fusion-MPT SPI host driver (mptspi) updated to 4.28.20.02.

     * LSI Fusion-MPT SAS 2.0 driver (mpt2sas) updated to
       17.00.01.00.

     * LSI Fusion-MPT SAS 3.0 driver (mpt3sas) version 3.00.00.00
       added. Supports up to 12 Gb/s host controllers.

MegaRAID


     * MegaRAID SAS driver (megaraid_sas) updated to 06.600.18.00.

QLogic


     * iSCSI driver (qla4xxx) updated to 5.03.00.03.06.02-uek2.
       Supports Open-iSCSI.

Xsigo


     * Core services module driver (xscore) version 6.0.r7269 added.
       Required by all other Xsigo modules.

     * Virtual HBA driver (xsvhba) version 6.0.r7269 added.

1.3.2. Network Adapter Drivers

Broadcom


     * Tigon3 Ethernet adapter driver (tg3) updated to 3.131d.

Emulex


     * Blade Engine 2 10Gbps adapter driver (be2net) updated to
       4.6.63.0u.

Intel


     * PRO/1000 PCI-Express Gigabit network adapter driver (e1000e)
       updated to 2.4.14.

     * Gigabit Ethernet network adapter driver (igb) updated to
       4.3.0.

     * Gigabit Linux driver (igbvf) updated to 2.3.2. Provides
       82576-based virtual function devices on kernels that support
       Single Root I/O Virtualization (SR-IOV).

     * 10 Gigabit PCI-Express network adapter driver (ixgbe) updated
       to 3.15.1.

QLogic


     * 1/10 GbE Converged/Intelligent Ethernet Adapter driver
       (qlcnic) updated to 5.2.43.

Xsigo


     * Core services module driver (xscore) version 6.0.r7269 added.
       Required by all other Xsigo modules.

     * Virtual Ethernet driver (xve) added.

     * Virtual NIC driver (xsvnic) version 0.316.0.r7269 added.

1.4. Technology Preview

   The following features included in the Unbreakable Enterprise
   Kernel Release 2 are still under development, but are made
   available for testing and evaluation purposes.

     * DRBD (Distributed Replicated Block Device)
       A shared-nothing, synchronously replicated block device (RAID1
       over network), designed to serve as a building block for high
       availability (HA) clusters. It requires a cluster manager (for
       example, pacemaker) for automatic failover.

     * Kernel module signing facility
       Applies cryptographic signature checking to modules on module
       load, checking the signature against a ring of public keys
       compiled into the kernel. GPG is used to do the cryptographic
       work and determines the format of the signature and key data.

     * Linux Containers (lxc)
       Based on the Linux Cgroups and name spaces functionality,
       containers allow you to safely and securely run multiple
       applications or instances of an operating system on a single
       host without risking them interfering with each other.
       Containers are lightweight and resource-friendly, which saves
       both rack space and power. In order to get started with
       containers, you need to install the lxc package, which is
       included in the package repository of the Unbreakable
       Enterprise Kernel.

     * Transcendent memory
       Transcendent Memory (tmem for short) provides a new approach
       for improving the utilization of physical memory in a
       virtualized environment by claiming underutilized memory in a
       system and making it available where it is most needed. From
       the perspective of an operating system, tmem is fast
       pseudo-RAM of indeterminate and varying size that is useful
       primarily when real RAM is in short supply. To learn more
       about this technology and its use cases, see the Transcendent
       Memory project page at http://oss.oracle.com/projects/tmem/.

1.5. Compatibility

   Oracle Linux maintains user-space compatibility with Red Hat
   Enterprise Linux, which is independent of the kernel version
   running underneath the operating system. Existing applications in
   user space will continue to run unmodified on the Unbreakable
   Enterprise Kernel Release 2 and no re-certifications are needed
   for RHEL certified applications.

   From UEK R2 quarterly update 3 (2.6.39-400) onward, support for
   IB, OFED, and RDS is integrated into the kernel. The OFED userland
   RPMs continue to be provided, but the kernel-ib and ofa-kernel
   RPMs are no longer required.

   The kernel ABI remains unchanged in all updates to UEK R2
   subsequent to quarterly update 3.

   To minimize impact on interoperability during releases, the Oracle
   Linux team works closely with third-party vendors whose hardware
   and software have dependencies on kernel modules. However, to
   allow the introduction of new drivers, there might be instances
   where changes must be made. Before installing this update, verify
   the support status of this release with your application vendor.

Chapter 2. Fixed and Known Issues

   This chapter describes the fixed and known issues for the
   Unbreakable Enterprise Kernel Release 2.
   Important

   Run the yum update command regularly to ensure that the latest bug
   fixes and security errata are installed on your system.

2.1. Fixed Issues

   This update includes minor fixes for various software issues as
   well as security fixes for several CVEs. There are no major fixed
   issues of note.

2.2. Known Issues

   This section describes known issues in this update.

ACPI

   One some systems you might see ACPI-related error messages in
   dmesg similar to the following:
ACPI Error: [CDW1] Namespace lookup failure, AE_NOT_FOUND
        ACPI Error: Method parse/execution failed [_SB_._OSC||\||]
        ACPI Error: Field [CDW3] at 96 exceeds Buffer [NULL] size 64
(bits)]]>

   These messages, which are not fatal, are caused by bugs in the
   BIOS. Contact your system vendor for a BIOS update. (Bug ID
   13100702)

ASM

   Calling the oracleasm init script, /etc/init.d/oracleasm, with the
   parameter scandisks can lead to error messages about missing
   devices similar to the following:
oracleasm-read-label: Unable to open device "device": No such file or
 directory

   However, the device actually exists. You can ignore this error
   message, which is triggered by a timing issue. Only use the init
   script to start and stop the oracleasm service. All other options,
   such as scandisks, listdisk, and createdisk, are deprecated. For
   these and other administrative tasks, use /usr/sbin/oracleasm
   instead. (Bug ID 13639337)

bnx2x driver

   When using the bnx2x driver in a bridge, disable Transparent
   Packet Aggregation (TPA) by including the statement options bnx2x
   disable_tpa=1 in /etc/modprobe.conf. (Bug ID 14626070)

Btrfs


     * Together with the UEK R2 kernel in quarterly update 4, a new
       version of the user-space btrfs-progs package
       (btrfs-progs-0.20-1.4) was provided on the ol6_latest channel.
       This package enabled command-line access to new btrfs
       features. If you install this version or later of the
       btrfs-progs package on a system that does not have an upgraded
       kernel, most of the new command functionality supported by the
       package fails with the error Inappropriate ioctl for device.
       The exception is the -l option to mkfs.btrfs, which requires
       version 2.6.39-400.109.1 or later of the Unbreakable
       Enterprise Kernel. Do not use this option with an non-upgraded
       kernel as correct functioning of the file system cannot be
       guaranteed. Although the leaf size appears to be set
       successfully, there is a risk of data corruption if you
       subsequently use the resulting file system. (Bug ID 16920640)

     * If you use the --alloc-start option with mkfs.btrfs to specify
       an offset for the start of the file system, the size of the
       file system should be smaller but this is not the case. It is
       also possible to specify an offset that is higher than the
       device size. This bug is present in the user-space btrfs-progs
       package (btrfs-progs-0.20-1.4). (Bug ID 16946255)

     * The usage information for mkfs.btrfs reports raid5 and raid6
       as possible profiles for both data and metadata. However, the
       kernel does not support these features and cannot mount file
       systems that use them. This bug is present in the user-space
       btrfs-progs package (btrfs-progs-0.20-1.4). (Bug ID 16946303)

     * The btrfs filesystem balance command does not warn that the
       RAID level can be changed under certain circumstances, and
       does not provide the choice of cancelling the operation. (Bug
       ID 16472824)

     * Converting an existing ext2, ext3, or ext4 root file system to
       btrfs does not carry over the associated security contexts
       that are stored as part of a file's extended attributes. With
       SELinux enabled and set to enforcing mode, you might
       experience many permission denied errors after reboot, and the
       system might be unbootable. To avoid this problem, enforce
       automatic file system relabeling to run at bootup time. To
       trigger automatic relabeling, create an empty file named
       .autorelabel (for example, by using touch) in the file
       system's root directory before rebooting the system after the
       initial conversion. The presence of this file instruct SELinux
       to recreate the security attributes for all files on the file
       system. If you forget to do this and rebooting fails, either
       temporarily disable SELinux completely by adding selinux=0 to
       the kernel boot parameters, or disable enforcing of the
       SELinux policy by adding enforcing=0. (Bug ID 13806043)

     * A failing RAID1 disk can result in a kernel panic with the
       error message:
BTRFS error (device (null)) in btree_writepage_io_failed_hook:3662: \
          IO failure (Error occurred while writing out btree at offse
t).
       (Bug ID 16262571)

     * The btrfs filesystem defragment command exits with an exit
       code of 20 even if it succeeds. (Bug ID 13714531)

     * Commands such as du can show inconsistent results for file
       sizes in a btrfs file system when the number of bytes that is
       under delayed allocation is changing. (Bug ID 13096268)

     * Btrfs has a limit of 237 or fewer hard links to a file from a
       single directory. The exact limit depends on the number of
       characters in the file name. The limit is 237 for a file with
       up to eight characters in its file name; the limit is lower
       for longer file names. Attempting to create more than this
       number of links results in the error Too many links. You can
       create more hard links to the same file from another
       directory. (Bug ID 16278563)

     * If you run the btrfs quota enable command on a non-empty file
       system, any existing files do not count toward space usage.
       Removing these files can cause usage reports to display
       negative numbers and the file system to be inaccessible. The
       workaround is to enable quotas immediately after creating the
       file system. If you have already written data to the file
       system, it is too late to enable quotas. (Bug ID 16569350)

     * The btrfs quota rescan command is not currently implemented.
       The command does not perform a rescan and returns without
       displaying any message.

     * The functionality to limit the space that is available to a
       quota group before compressing the subvolume is not yet
       implemented. The -c option (limit the space after compression)
       to the btrfs qgroup limit command is implicitly enabled. (Bug
       ID 16569387)

     * The copy-on-write nature of btrfs means that every operation
       on the file system initially requires disk space. It is
       possible that you cannot execute any operation on a disk that
       has no space left; even removing a file might not be possible.
       The workaround is to run sync before retrying the operation.
       If this does not help, remount the file system with the -o
       nodatacow option and delete some files to free up space. See
       https://btrfs.wiki.kernel.org/index.php/ENOSPC.

     * The seed-device functionality of btrfs causes a kernel panic
       when the btrfs device add command is run. There is currently
       no known workaround for this issue. (Bug ID 17334251)

CPU microcode update failures on PVM/PVHVM guests

   When running Oracle Linux with UEK R2, you might see error
   messages in dmesg or /var/log/messages similar to this one:
microcode: CPU0 update to revision 0x6b failed.

   You can ignore this warning. You do not need to upgrade the
   microcode for virtual CPUs as presented to the guest. (Bug ID
   12576264, 13782843)

DHCP lease is not obtained at boot time

   If DHCP lease negotiation takes more than 5 seconds at boot time,
   the following message is displayed:
ethX: failed. No link present. Check cable?

   If the ethtool ethX command confirms that the interface is
   present, edit /etc/sysconfig/network-scripts/ifcfg-ethX and set
   LINKDELAY=N, where N is a value greater than 5 seconds (for
   example, 30 seconds). Alternatively, use NetworkManager to
   configure the interface. (Bug ID 16620177)

Emulex OneConnect UCNA Firmware Flashing

   The request_firmware interface to the Emulex Ethernet driver for
   Emulex OneConnect adapters supports flash updating of the UCNA
   firmware image.

   Oracle Linux 5 systems with the Unbreakable Enterprise Kernel
   require the ethtool-6-4.0.1.el5.arch.rpm version of the ethtool
   package, where arch is i386 or x86_64 as appropriate. The package
   is available from the ol5_i386_UEK_latest and
   ol5_x86_64_UEK_latest channels on the Unbreakable Linux Network
   (Advisory ELBA-2013-2544
   (https://oss.oracle.com/pipermail/el-errata/2013-August/003651.htm
   l), released Aug 29, 2013) or from Oracle Public Yum at
   http://public-yum.oracle.com/repo/OracleLinux/OL5/latest.

   Oracle Linux 6 systems with the Unbreakable Enterprise Kernel do
   not require a package update.
   Note

   You can update the firmware image while the UCNA is online and
   passing network or storage traffic. However, you must reboot the
   system for the new firmware image to take effect.

   To update the UCNA firmware image:

    1. Copy the firmware image file (for example, be3flash.ufi) to
       the /lib/firmware directory:

	# cp be3flash.ufi /lib/firmware

    2. Start the update process:

	# ethtool -f ethN be3flash.ufi 0
       where ethN is the name of the interface.

    3. Reboot the system to enable the new firmware image to take
       effect.

Firmware warning message

   You can safely ignore the following firmware warning message that
   might be displayed on some Sun hardware:
[Firmware Warn]: GHES: Poll interval is 0 for generic hardware error
source:
1, disabled.

   (Bug ID 13696512)

I/O scheduler

   The Unbreakable Enterprise Kernel uses the deadline scheduler as
   the default I/O scheduler. For the Red Hat Compatible Kernel, the
   default I/O scheduler is the cfq scheduler.

InfiniBand warning messages when disabling a switch port

   You might see the following warning messages if you use the
   ibportstate disable command to disable a switch port:
ibwarn: [2696] _do_madrpc: recv failed: Connection timed out
ibwarn: [2696] mad_rpc: _do_madrpc failed; dport (Lid 38)
ibportstate: iberror: failed: smp set portinfo failed

   You can safely ignore these warnings. (Bug ID 16248314)

libfprint

   The following message might appear in dmesg or /var/log/messages:
WARNING! power/level is deprecated; use power/control instead.

   The USB subsystem in UEK R2 deprecates the power/level sysfs
   attribute in favor of the power/control attribute. The libfprint
   fingerprinting library triggers this warning via udev rules that
   try to use the old attribute first. You can safely ignore this
   warning. The setting of the appropriate power level still
   succeeds. (Bug ID 13523418)

Multipathed root disk

   At boot time, the root file system is not writable when the
   multipathing service starts. As a result, the system cannot
   automatically generate the file /etc/multipath/wwids and the
   console displays a message similar to the following:
Cannot open file [/etc/multipath/wwids] readonly: No such file or dir
ectory

   You can safely ignore this warning. The subsequent post-boot
   operation of multipathd and device-mapper-multipath is not
   affected.

   To prevent this warning message from recurring, enter the
   following command as root to generate /etc/multipath/wwids after
   the system has booted:

	# multipath -l

   (Bug ID 17395420, 16076888)

NFSv4 and open(2) flag combinations that can cause a process to hang

   If you specify both the O_RDONLY and O_TRUNC flags when opening a
   regular file in a mounted NFS version 4 file system,the calling
   process hangs. The workaround is not to use this combination of
   flags with regular files. O_TRUNC is intended for use with regular
   files where the open mode allows writing. (Bug ID 17412390)

Nouveau kernel driver is not compatible with NVIDIA graphics driver

   After upgrading to UEK R2, the NVIDIA driver upgrade script does
   not correctly blacklist the Nouveau kernel driver. To blacklist
   the driver, append rdblacklist=nouveau nouveau.modeset=0 to the
   kernel boot parameters in /boot/grub/grub.conf.

NUMA warning messages on a non-NUMA system

   You can safely ignore the following warning messages in dmesg and
   /var/log messages if you see them on a non-NUMA system:
kernel: NUMA: Warning: node ids are out of bound, from=-1 to=-1 dista
nce=10
hcid[4293]: Register path:/org/bluez fallback:1
kernel: No NUMA configuration found

   (Bug ID 13711370)

pcspkr driver error message

   You can safely ignore the following error message:
Error: Driver 'pcspkr' is already registered, aborting...

   The message arises from an alias conflict between snd-pcsp and
   pcspkr. To prevent the message from being displayed, add the
   following line to /etc/modprobe.d/blacklist.conf:
blacklist snd-pcsp

   (Bug ID 10355937)

sched_yield() settings for CFS

   For the Unbreakable Enterprise Kernel, kernel.sched_compat_yield=1
   is set by default. For the Red Hat Compatible Kernel,
   kernel.sched_compat_yield=0 is used by default.

Soft lockup errors when booting

   When upgrading or installing the UEK R2 kernel on fast hardware,
   usually with SAN storage attached, the kernel can fail to boot and
   BUG: soft lockup messages are displayed in the console log. The
   workaround is to increase the baud rate from the default value of
   9600 by amending the kernel boot line in /boot/grub/grub.conf to
   include an appropriate console setting, for example:
console=ttyS0,115200n8

   A value of 115200 is recommended as smaller values such as 19200
   are known to be insufficient for some systems (for example, see
   http://docs.oracle.com/cd/E19045-01/blade.x6220/820-0048-18/sp.htm
   l#0_pgfId-1002490). If the host implements an integrated system
   management infrastructure, such as ILOM on Sun and Oracle systems
   or iLO on HP systems, configure the integrated console baud rate
   to match the setting for the host system. Otherwise, the
   integrated console is likely to display garbage characters. (Bug
   ID 17064059, 17252160)

Support for large memory 32-bit systems

   Releases of Oracle Linux prior to Oracle Linux 5 supplied a
   hugemem kernel to allow a system to address up to 64 GB of memory
   in 32-bit mode. The hugemem kernel is no longer available in
   Oracle Linux 5 and later releases.

   The Unbreakable Enterprise Kernel (UEK) supports a maximum of 16
   GB of memory for 32-bit kernels on bare metal and hardware
   virtualized machine (HVM) systems, and 8 GB for fully
   paravirtualized machine (PVM) systems. 32-bit PVM guest operating
   systems must be located in the first 128 GB of physical memory on
   the host.

   The Red Hat Compatible Kernel (RHCK) has the same limitations,
   except that PVM systems can have up to 16 GB of memory. The
   limitation of 8 GB for PVM on UEK was chosen for reasons of
   reliability.

   A 32-bit system uses the PAE (physical address extension) memory
   feature to map physical memory beyond 4 GB into the 32-bit address
   space that is available to each process. A 64-bit system can
   address memory beyond 4 GB without requiring an extra layer of
   memory abstraction.

   Oracle Linux on x86_64 includes 32-bit libraries, which allow
   applications built for both 64-bit and 32-bit Linux to run on the
   same system. This capability provides scalability to virtually
   unlimited memory sizes, while retaining the ability to run 32-bit
   applications. Oracle recommends this configuration for any system
   with more than 4 GB of memory. (Bug ID 16974301)

Transparent Huge Pages

   This update removes the Transparent Huge Pages (THP) feature.
   Following extensive benchmarking and testing, Oracle found that
   THP caused a performance degradation for some workloads of between
   5 and 10%. This performance degradation was a result of a slower
   memory allocator code path being used even when the applications
   were not using THP. When the fact that huge pages are not
   swappable was taken into account, the positive effect that THP
   should provide was outweighed by its negative effects.

   After installing this update, you cannot enable THP (for example,
   by specifying kernel boot parameters). The THP settings under
   /sys/kernel/mm/transparent_hugepage have also been removed. A
   future update might contain an updated THP implementation which
   resolves the performance issue.
   Note

   This change does not affect support for applications that use
   explicit huge pages (for example, Oracle Database).

   (Bug ID 17279055)

udev

   A message similar to the following might be recorded in dmesg or
   /var/log/messages at boot time:
udevd (pid): /proc/pid/oom_adj is deprecated, please use /proc/pid/oo
m_score_adj instead.

   The udev process uses the deprecated oom_adj kernel interface to
   prevent it from being killed if the system runs short of memory.
   You can safely ignore the message as the action still succeeds. To
   prevent the message from occurring, install the package
   udev-147-2.42.el6.arch.rpm or higher for Oracle Linux 6, or
   udev-095-14.29.0.1.el5.arch.rpm or higher for Oracle Linux 5. (Bug
   ID 13655071, 13712009)

Virtualization


     * When booting UEK R2 as a PVHVM guest, you can safely ignore
       the following kernel message:
register_vcpu_info failed:
          err=-38
       (Bug ID 13713774)

     * Under Oracle VM Server 3.1.1, migrating a PVHVM guest that is
       running the UEK R2 Quarterly Update 5 kernel causes a
       disparity between the date and time as displayed by date and
       hwclock. The workaround post migration is either to run the
       command hwclock --hctosys on the guest or to reboot the guest.
       (Bug ID 16861041)

     * Under Oracle VM Server 2.2.2, increasing the memory that is
       assigned to an Oracle Linux 6 Update 4 x86_64 HVM guest
       running UEK R2 Quarterly Update 5 causes the guest to reboot.
       There is no known workaround for this issue. (Bug ID 17440635)

XFS


     * Reading from or writing to a zero or null device on a
       read-only XFS file system fails with the following error:
XFS_IOC_FSGEOMETRY: Inappropriate ioctl for device
       (Bug ID 16970090)

     * Newly created directories in an XFS file system do not inherit
       their group setting from the parent directory on which the
       setgid bit is set. (Bug ID 17423815)

Chapter 3. Installation and Availability

   The Unbreakable Enterprise Kernel Release 2 Quarterly Update 5 can
   be installed on Oracle Linux 5 Update 8 or newer, as well as
   Oracle Linux 6 Update 2 or newer, both running either the Red Hat
   compatible kernel or a previous version of the Unbreakable
   Enterprise Kernel. If you are still running an older version of
   Oracle Linux, first update your system to the latest available
   update release.

   The kernel images are available as binary RPM packages from
   dedicated channels on Oracle's Unbreakable Linux Network (ULN) as
   well as the Oracle Public Yum repository. Four channels are
   available:


     * Oracle Linux 5 (x86): ol5_i386_UEK_latest

     * Oracle Linux 5 (x86_64): ol5_x86_64_UEK_latest

     * Oracle Linux 6 (x86): ol6_i386_UEK_latest

     * Oracle Linux 6 (x86_64): ol6_x86_64_UEK_latest

   If your system is registered with ULN, make sure you subscribe it
   to the appropriate UEK_latest channel.

   For Oracle Public Yum, the appropriate UEK_latest channel is
   automatically enabled in the yum respiratory file under
   /etc/yum.repos.d when you install Oracle Linux 5 update 9 or later
   and Oracle Linux 6 update 3 or later.

   To upgrade an existing Oracle Linux 5 or Oracle Linux 6
   installation to the latest UEK R2, enable the appropriate
   UEK_latest channel and run yum update.

   For detailed instructions on how to download and install the
   Unbreakable Enterprise Kernel on Oracle Linux see the Getting
   Started with the Unbreakable Enterprise Kernel for Oracle Linux
   document on the Oracle Technology Network (OTN) at
   http://www.oracle.com/technetwork/articles/servers-storage-admin/u
   ek-rel2-getting-started-1555632.html.

   If you have questions regarding configuring or using yum to
   install updates, refer to the Oracle Linux Administrator's
   Solutions Guide at http://docs.oracle.com/cd/E37670_01/index.html.

   For information about using ULN, see the Oracle Linux Unbreakable
   Linux Network User's Guide at
   http://docs.oracle.com/cd/E37670_01/index.html.

   The kernel's source code is available via a public git source code
   repository at http://oss.oracle.com/git/?p=linux-uek-2.6.39.git.

   Copyright (c) 2013, Oracle and/or its affiliates. All rights
   reserved. Legal Notices