Oracle® Linux
Release Notes for Unbreakable Enterprise Kernel Release 2 Quarterly
Update 3
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E39869-01
February 2013
Abstract
This document contains information on Quarterly Update 3 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: 2013-02-27 (revision: 615)
_______________________________________________________
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. It is based
on the mainline Linux 3.0 version 3.0.36. It contains a large
number of improvements and new features that have been
incorporated into mainline Linux since the first version of the
Unbreakable Enterprise Kernel, which was based on Linux 2.6.32.
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 these changes.
The 2.6.39-400 release is a quarterly driver update release which
also includes bug and security fixes.
Note
The actual 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 not
aware or affected by Linux kernel version numbers.
1.1. Notable Changes
* The code base has been aligned with mainline Linux 3.0.36.
* Support for the SGI UV 2 architecture has been added.
* Support for family 15H model 2 (Abu Dhabi) AMD processors has
been added.
* NBD, the network block device driver has been updated and
enabled (CONFIG_BLK_DEV_NBD=m).
* The following InfiniBand hardware is supported with the
Unbreakable Enterprise Kernel:
+ Mellanox ConnectX-2 InfiniBand Host Channel Adapters
+ Sun InfiniBand QDR Host Channel Adapter PCIe #375-3696
* The QLogic iSCSI driver (qla4xxx) has been updated to support
Open-iSCSI.
1.2. Xen Improvements
Several improvements have been incorporated into the Unbreakable
Enterprise Kernel to support Xen usage:
* Numerous bug fixes and performance improvements.
* Added support for more than 128 GB in a PV guest.
* Xen Machine Check Exception (MCE) driver added (allows you to
view MCE events that the Xen hypervisor receives).
* Xen Physical CPU (PCPU) driver added (allows management tools
to online or offline physical CPUs in dom0).
* Xen Processor Aggregator Device (PAD) added (enables
configuration and control of all processors on a platform).
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
Broadcom
* NetXtreme II iSCSI driver (bnx2i) updated to 2.7.4.1f.
* NetXtreme II Fibre Channel over Ethernet driver (bnx2fc)
updated to 2.2.17.
Emulex
* Blade Engine 2 Open-iSCSI driver (be2iscsi) updated to
10.0.272.0o.
* Fibre Channel HBA driver (lpfc) updated to 8.3.5.86.2p.
Mellanox
* ConnectX core driver (mlx4_core) released at 1.0-ofed1.5.5
(x86_64 only). Handles low-level functions such as device
initialization and firmware commands processing, and controls
resource allocation so that the InfiniBand and Ethernet
functions can share a device without interfering with each
other.
* ConnectX Ethernet driver (mlx4_en) released at 1.5.4.24
(x86_64 only). Handles Ethernet-specific functions and plugs
into the netdev mid-layer.
* ConnectX InfiniBand driver (mlx4_ib) released at 1.0-ofed1.5.5
(x86_64 only). Handles InfiniBand-specific functions.
QLogic
* Fibre Channel HBA driver (qla2xxx) updated to
8.04.00.11.39.0-k.
* iSCSI driver (qla4xxx) updated to 5.03.00.01.06.02-uek2. Now
supports Open-iSCSI.
1.3.2. Network Adapter Drivers
Broadcom
* NetXtreme II network adapter driver (bnx2) updated to 2.2.3e.
* NetXtreme II 10Gbps network adapter driver (bnx2x) updated to
1.74.17.
* Converged Network Interface Card core driver (cnic) updated to
2.5.12e.
* Tigon3 Ethernet adapter driver (tg3) updated to 3.125g.
Emulex
* Blade Engine 2 10Gbps adapter driver (be2net) updated to
4.4.161.0o.
Intel
* PRO/1000 PCI-Express Gigabit network adapter driver (e1000e)
updated to 2.1.4-NAPI.
* Gigabit Ethernet network adapter driver (igb) updated to
4.0.17.
* 10 Gigabit PCI-Express network adapter driver (ixgbe) updated
to 3.11.33.
* 10 Gigabit Server Adapter virtual function driver (ixgbevf)
updated to 2.6.2-NAPI. The kernel must support Single Root I/O
Virtualization (SR-IOV).
QLogic
* NetXen Multiport 1/10 Gigabit Network adapter driver
(netxen_nic) updated to 4.0.80.
* 1/10 GbE Converged/Intelligent Ethernet Adapter driver
(qlcnic) updated to 5.1.27.35.
* QLE81xx network adapter driver (qlge) updated to v1.00.00.31.
1.3.3. Miscellaneous Drivers
Oracle
* Reliable Datagram Sockets driver (rds) updated to 4.1. RDS
provides in-order, non-duplicated, highly-available,
low-overhead, reliable delivery of datagrams between hundreds
of thousands of non-connected endpoints.
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
will continue to run unmodified on the Unbreakable Enterprise
Kernel Release 2 and no re-certifications are needed for RHEL
certified applications.
The Oracle Linux team works closely with third-party hardware and
software vendors to minimize impact on interoperability during
releases but in order to introduce new drivers there are instances
where changes must be made. In this release, there are changes to
the kernel ABI which requires third-party kernel modules on the
system be recompiled. 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.
2.1. Fixed Issues
The following issues have been fixed in this update.
* The legacy DNS resolver now supports the sending of NFSv4
referrals (lists of NFS servers and exported NFS file systems)
to Oracle Linux 6 clients. The user-space component in the
nfs-utils package is distributed with Oracle Linux 6 Update 4.
(Bug ID 14769650)
* A bug has been fixed that caused connections to hang when
running SysBench benchmarks on MySQL with the thread pool
enabled. (Bug ID 16363540)
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
* Running btrfs filesystem balance converts a non-RAID or
concatenated file system setup to RAID-0 after adding a new
device. (Bug ID 13715389)
* 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 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 offse
t).
(Bug ID 16262571)
* The btrfs subvolume get-default command lists all existing
subvolumes instead of only the default subvolume. (Bug ID
13815433)
* The btrfs filesystem defragment command exits with an exit
code of 20 even if it succeeds. (Bug ID 13714531)
* 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 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)
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)
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.
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)
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.
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.
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 and 13712009)
Virtualization
When booting UEK R2 as a 32-bit PVHVM guest, you can safely ignore
the following kernel message:
register_vcpu_info failed:
err=-38
(Bug ID 13713774)
Chapter 3. Installation and Availability
The Unbreakable Enterprise Kernel Release 2 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 as well
as the 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
Existing Oracle Linux 5 or Oracle Linux 6 installations can be
upgraded to UEK R2 by enabling the appropriate UEK_latest channel
and running yum update. The channel is automatically enabled for
freshly installed Oracle Linux 6 Update 3 systems that shipped
with the 2.6.39-200 kernel version of UEK R2.
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.
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