2.2 Known Issues

This section describes known issues in this update.

Kernel Panic with Emulex LPe16XXX and Sun Storage FCoE Adapters

A kernel panic can occur at boot time if the UEK kernel is older than UEK R2 QU5 (2.6.39-400.209.1) and one of the following FCoE adapters is installed on the system:

  • Emulex LPe16002-M6-O 2-Port 10Gb FCoE Adapter

  • Emulex LPem16002-M6-O 2-Port 10Gb FCoE Adapter

  • Emulex LPe16202-X 2-Port 10Gb FCoE Adapter

  • Sun Storage 16Gb FC ExpressModule Universal HBA-Emulex (#7101689 and #7101690)

  • Sun Storage 16Gb FC PCIe Universal HBA-Emulex (#7101683 and #7101684)

The panic occurs because these adapters require version 0: or later of the lpfc driver.

To resolve this issue, update the kernel to UEK R2 QU5 (2.6.39-400.209.1), UEK R3 (3.8.13-16), or later release, which include an updated version of the lpfc driver.

Oracle Clusterware Fails to Start on ASM Storage with SELinux Enabled

If the SELinux policy packages have not been updated recently, Cluster Ready Services (CRS) might fail to start with messages such as the following in /var/log/messages:

SELinux is preventing /usr/lib/oracleasm/oracleasm-instantiate-disk from
associate access on the filesystem DATA1.

The solution is to upgrade the selinux-policy and selinux-policy-targeted packages to ensure that you are running a version no earlier than

# yum update 'selinux-policy*'

After upgrading the packages, reboot the system. (Bug ID 13925445)

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)

Linux Containers 32-bit Support

The Linux Containers package (lxc) is not available for the i386 architecture.

Linux Containers Interoperability with SELinux

Running with SELinux enabled on the host can cause issues with Linux Containers. The workaround is to disable SELinux altogether by setting SELINUX=disabled in /etc/selinux/config and rebooting the system. Using the setenforce Permissive command is not sufficient as the selinuxfs pseudo file system remains mounted. (Bug ID 15967411)

Linux Containers Default Configuration Location

The default location for a container's configuration has changed from /etc/lxc/name to /container/name in lxc 0.8.0.

To start a container that you created with a previous update of Oracle Linux, specify the -f option to lxc-start, for example:

# lxc-start -n ol6u3 -f /etc/lxc/ol6u3/config

To convert an existing container to use the new location:

  1. Move the container's configuration directory to /container/name:

    # mv /etc/lxc/name /container 
  2. Edit the /container/name/config file and change the values of any lxc.rootfs and lxc.mount parameters to refer to /container instead of /etc/lxc.

    For example, if the config file contained the following entries:

    lxc.rootfs = /etc/lxc/example/rootfs
    lxc.mount.entry=/lib /etc/lxc/example/rootfs/lib none ro,bind 0 0
    lxc.mount.entry=/usr/lib /etc/lxc/example/rootfs/usr/lib none ro,bind 0 0
    lxc.mount.entry=/lib64 /etc/lxc/example/rootfs/lib64 none ro,bind 0 0
    lxc.mount.entry=/usr/lib64 /etc/lxc/example/rootfs/usr/lib64 none ro,bind 0 0

    you would change these entries to read:

    lxc.rootfs = /container/example/rootfs
    lxc.mount.entry=/lib /container/example/rootfs/lib none ro,bind 0 0
    lxc.mount.entry=/usr/lib /container/example/rootfs/usr/lib none ro,bind 0 0
    lxc.mount.entry=/lib64 /container/example/rootfs/lib64 none ro,bind 0 0
    lxc.mount.entry=/usr/lib64 /container/example/rootfs/usr/lib64 none ro,bind 0 0

After converting the container, you do not need to specify the -f option to lxc-start. (Bug ID 15967411)

Broadcom NetXtreme II 10Gbps Network Adapter Driver

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

Btrfs File System Balancing

Running btrfs filesystem balance converts a non-RAID or concatenated file system setup to RAID-0 after adding a new device. Do not run this command if you do not intend to convert the profile of the file system after adding the new device. (Bug ID 13715389)

Btrfs Conversion Does Not Preserve SELinux Security Contexts

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 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)

Btrfs RAID1 Failure Results in a Kernel Panic

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

btrfs subvolume get-default Command

The btrfs subvolume get-default command lists all existing subvolumes instead of only the default subvolume. (Bug ID 13815433)

btrfs filesystem defragment Command

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

Btrfs File Size

Commands such as du might 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 Hard Link Limit

Btrfs has a limit of 237 hard links to a file. Attempting to create more than this number of links results in the error Too many links. (Bug ID 16278563)

Error Message Following First Reboot on an HP ProLiant Server

You might see a message similar to the following during the first reboot of an HP ProLiant server:

[Firmware Bug]: the BIOS has corrupted hw-PMU resources (MSR 186 is 43003c)

You can safely ignore this message. The functionality and performance of the operating system and the server are not affected.

Mellanox ConnectX Drivers

The Mellanox ConnectX core, Ethernet, and InfiniBand drivers are supported only for the x86_64 architecture.

(Bug ID 16228063)

udevd Message

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/oom_score_adj instead.

The udevd 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. (Bug ID 13655071, 13712009)

Unable to Register Oracle Linux Guest with ULN

Registering an Oracle Linux guest running under Virtual Box with the Unbreakable Linux Network (ULN) might fail with a server communication error. The workaround is to run the following command as root on the guest:

# echo "uuid=`uuidgen -t`" >> /etc/sysconfig/rhn/up2date

and then run uln_register again. (Bug ID 14696776)

xguest Package Not Installable with SELinux Disabled

If the xguest package fails to install with a PREIN script error, enable SELinux by setting SELINUX=enabled in /etc/selinux/config, reboot the system, and reinstall the xguest package. (Bug ID 13495388)

X Window System Does Not Run in a PVHVM guest

If you install an Oracle Linux 6 Update 4 (x86_64) PVHVM guest with either the Desktop or the Software Development Workstation installation options, the X Window System is not accessible after installation when you boot the guest into run level 5. This problem is seen in OVM 3.0 and later.

Use the following workaround:

  1. Boot the guest into run level 3 by appending 3 to the kernel command line in GRUB, for example:

    kernel /vmlinuz-2.6.39-400.15.0.el6uek.x86_64 ... rd_NO_DM 3

  2. After the guest boots, log in as root, and uninstall the xorg-x11-drv-cirrus package, for example:

    # rpm -ev --nodeps xorg-x11-drv-cirrus

You can then either reboot the system into run level 5 or use the init 5 command to switch to run level 5. The X Window System will be accessible on subsequent boots to run level 5. (Bug ID 16280196)

Oracle VM 3.0 Guests Crash During Oracle Database Installation

PVHVM guests on Oracle VM 3.0 crash during Oracle Database installation if the value of the maximum memory (maxmem) parameter set for the guest is greater than the amount specified at boot time (memory). To avoid this issue, ensure that the values of the maxmem and memory parameters are the same. This issue has been resolved in Oracle VM 3.1.1. (Bug ID 13396734)

Booting UEK R2 as a 32-bit PVHVM guest

When booting UEK R2 as a 32-bit PVHVM guest, you can safely ignore the kernel message register_vcpu_info failed: err=-38, which might be displayed. (Bug ID 13713774)

Post-installation Anaconda Errors

In certain cases, after successfully completing installation and rebooting the system, it is possible for errors such as the following to occur:

Error in sys.excepthook:
 Traceback (most recent call last):
   File "/usr/lib/python2.6/site-packages/meh/handler.py", line 161, in
   File "/usr/lib/anaconda/exception.py", line 44, in handleException
   File "/usr/lib/python2.6/site-packages/meh/handler.py", line 106, in
   File "/usr/lib/anaconda/gui.py", line 1169, in mainExceptionWindow
 ImportError: No module named ui.gui
14:05:55 CRITICAL: anaconda exception report
Traceback (most recent call first):
  File "/usr/lib64/python2.6/site-packages/gtk-2.0/gtk/_lazyutils.py", line 32,
in __
  File "/usr/lib/anaconda/gui.py", line 1453, in keyRelease
    if ((event.keyval == gtk.keysyms.KP_Delete
ImportError: No module named keysyms

These errors can safely be ignored.

FCoE Target Service

The upstream release has added support for FCoE target service. This service is not supported with the previous release of the Unbreakable Enterprise Kernel (2.6.32). To use this service, boot your system into the Unbreakable Enterprise Kernel Release 2 (2.6.39) or the Red Hat Compatible Kernel.

mlx4_core Conflicts Between the mlnx_en and ofa Packages

Both the mlnx_en and ofa packages contain mlx4_core. Only one of these packages should be installed. Attempting to install both packages on a single server results in a package conflict error. If you have a Mellanox Ethernet Controller, install mlnx_en. If you have a Mellanox InfiniBand Controller, install ofa. If your system has both controllers, use ofa as it supports both the Ethernet and InfiniBand controllers.

Kdump Service Fails to Start for UEK

When configuring the crash kernel for the UEK, only standard crash kernel settings (for example, crashkernel=128M@32M) are supported. The new settings used by the Red Hat Compatible Kernel (for example, crashkernel=auto) are not supported and cause the kdump service to fail to start. (Bug ID 13495212)

iTCO_wdt Errors

If you see the boot-time dmesg error iTCO_wdt: failed to reset NO_REBOOT flag, device disabled by hardware/BIOS with UEK R2 or iTCO_wdt: failed to reset NO_REBOOT flag, reboot disabled by hardware with UEK, add the line blacklist iTCO_wdt to /etc/modprobe.d/blacklist-watchdog.

Paravirtualized Drivers in a Hardware Virtualized Guest

The Unbreakable Enterprise Kernel adds support for PV drivers in a HVM guest (PVHVM) on Oracle VM. The default is to present only PV drivers when running in an HVM guest. To run kernel-uek fully hardware virtualized, including the drivers, add the parameter xen_emul_unplug=never to the boot parameters in /etc/grub.conf, for example:

kernel /vmlinuz-2.6.32-300.2.1.el6uek ro root=/dev/VolGroup00/LogVol00 xen_emul_unplug=never

Adding this parameter makes the kernel also present the emulated drivers as previously (for example, the 8139cp network driver).

Incorrect Package Count

Selecting all packages in certain groups during installation might not show the correct package count. (Bug ID 11684244)

Default Reverse Path Filtering Mode Affects Certain Oracle Products

Oracle Linux 6 defaults to reverse path filtering in strict mode. Some Oracle products and network storage devices work more reliably with reverse path filtering in loose mode. To enable loose mode, issue the following command (where iface is the network interface, for example, eth1).

# sysctl net.ipv4.conf.iface.rp_filter=2

The default setting is 1 for strict mode. (Bug ID 10649976)

Receive Packet Steering errors

Certain network operations that utilize receive packet steering could cause errors on the system. (Bug ID 11071685)

Spurious udev Messages During Failed Path Restoration

If failed paths are restored in a multipath configuration, you might see udevd-work error messages in /var/log/messages. The failed paths are restored despite these messages, which you can ignore. (Bug ID 11682171)

Default NFS Mount Options

The default NFS mount option has changed to NFS v4. To mount an NFS v3 volume (the default in Oracle Linux 5), use the following mount options:

-o vers=3,mountproto=tcp

Setting the Serial Console in a Hardware Virtualized Guest

To set the serial console a hardware virtualized guest, use following settings in the guest:

  • Add the following parameters to the kernel boot line in /etc/grub.conf:

    console=tty0 console=ttyS0,57600n8
  • Add the following line to /etc/securetty:


Oracle RDBMS Server 11gR2 Preinstall Settings Not Visible After Installation

On an x86_64 system, if you install the pam.i386 package either manually or via a package dependency, and the oracle-rdbms-server-11gR2-preinstall package is also selected, this overwrites the settings for Oracle Database in /etc/security/limits.conf. This is most likely to occur during a Kickstart-automated installation that includes non-standard packages. To restore the settings, run the oracle-rdbms-server-11gR2-preinstall-verify script. (Bug ID 14212822)

Unbreakable Linux Network

Following the first reboot after installing Oracle Linux 6, you are prompted to register your system with the Unbreakable Linux Network (ULN). If you did not configure your network during the installation, the registration process to ULN cannot succeed. To register your system, log in as root, configure the system's network manually, and run uln_register.

Console Appears to Hang When Booting

On some hardware, the console may appear to hang during the boot process after starting udev. However, the system does boot properly and is accessible. A workaround to this problem is to add nomodeset as a kernel boot parameter in /etc/grub.conf. (Bug ID 10094052, 13485328)

Default I/O Scheduler

For the Unbreakable Enterprise Kernel, deadline is the default I/O scheduler.

For the Red Hat Compatible Kernel, cfq is the default I/O scheduler.

sched_yield() Settings for Completely Fair Scheduler

For the Unbreakable Enterprise Kernel, the default setting is kernel.sched_compat_yield=1.

For the Red Hat Compatible Kernel, the default setting is kernel.sched_compat_yield=0.