Oracle® Linux
Release Notes for Unbreakable Enterprise Kernel Release 3 Quarterly
Update 1
Copyright (c) 2014, Oracle and/or its affiliates. All rights
reserved.
Oracle Legal Notices
Copyright Notice
Copyright (c) 1994-2014, Oracle and/or its affiliates. All rights
reserved.
Trademark Notice
Oracle and Java are registered trademarks of Oracle and/or its
affiliates. Other names may be trademarks of their respective
owners.
Intel and Intel Xeon are trademarks or registered trademarks of
Intel Corporation. All SPARC trademarks are used under license and
are trademarks or registered trademarks of SPARC International,
Inc. AMD, Opteron, the AMD logo, and the AMD Opteron logo are
trademarks or registered trademarks of Advanced Micro Devices.
UNIX is a registered trademark of The Open Group.
License Restrictions Warranty/Consequential Damages Disclaimer
This software and related documentation are provided under a
license agreement containing restrictions on use and disclosure
and are protected by intellectual property laws. Except as
expressly permitted in your license agreement or allowed by law,
you may not use, copy, reproduce, translate, broadcast, modify,
license, transmit, distribute, exhibit, perform, publish, or
display any part, in any form, or by any means. Reverse
engineering, disassembly, or decompilation of this software,
unless required by law for interoperability, is prohibited.
Warranty Disclaimer
The information contained herein is subject to change without
notice and is not warranted to be error-free. If you find any
errors, please report them to us in writing.
Restricted Rights Notice
If this is software or related documentation that is delivered to
the U.S. Government or anyone licensing it on behalf of the U.S.
Government, the following notice is applicable:
U.S. GOVERNMENT END USERS: Oracle programs, including any
operating system, integrated software, any programs installed on
the hardware, and/or documentation, delivered to U.S. Government
end users are "commercial computer software" pursuant to the
applicable Federal Acquisition Regulation and agency-specific
supplemental regulations. As such, use, duplication, disclosure,
modification, and adaptation of the programs, including any
operating system, integrated software, any programs installed on
the hardware, and/or documentation, shall be subject to license
terms and license restrictions applicable to the programs. No
other rights are granted to the U.S. Government.
Hazardous Applications Notice
This software or hardware is developed for general use in a
variety of information management applications. It is not
developed or intended for use in any inherently dangerous
applications, including applications that may create a risk of
personal injury. If you use this software or hardware in dangerous
applications, then you shall be responsible to take all
appropriate fail-safe, backup, redundancy, and other measures to
ensure its safe use. Oracle Corporation and its affiliates
disclaim any liability for any damages caused by use of this
software or hardware in dangerous applications.
Third-Party Content, Products, and Services Disclaimer
This software or hardware and documentation may provide access to
or information on content, products, and services from third
parties. Oracle Corporation and its affiliates are not responsible
for and expressly disclaim all warranties of any kind with respect
to third-party content, products, and services. Oracle Corporation
and its affiliates will not be responsible for any loss, costs, or
damages incurred due to your access to or use of third-party
content, products, or services.
Alpha and Beta Draft Documentation Notice Disclaimer
If this document is in preproduction status:
This documentation is in preproduction status and is intended for
demonstration and preliminary use only. It may not be specific to
the hardware on which you are using the software. Oracle
Corporation and its affiliates are not responsible for and
expressly disclaim all warranties of any kind with respect to this
documentation and will not be responsible for any loss, costs, or
damages incurred due to the use of this documentation.
E51472-02
February 2014
Abstract
This document contains information on Quarterly Update 1 to the
Unbreakable Enterprise Kernel Release 3. 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 3 with Oracle Linux 6. Oracle recommends
that you read this document before installing or upgrading the
Unbreakable Enterprise Kernel Release 3.
Document generated on: 2014-02-14 (revision: 1671)
_______________________________________________________
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 3.
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
the Oracle Accessibility Program website at
http://www.oracle.com/pls/topic/lookup?ctx=acc&id=docacc.
Access to Oracle Support
Oracle customers have access to electronic support through My
Oracle Support. For information, visit
http://www.oracle.com/pls/topic/lookup?ctx=acc&id=info or visit
http://www.oracle.com/pls/topic/lookup?ctx=acc&id=trs if you are
hearing impaired.
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.
Conventions
The following text conventions are used in this document:
Convention
Meaning
boldface
Boldface type indicates graphical user interface elements
associated with an action, or terms defined in text or the
glossary.
italic
Italic type indicates book titles, emphasis, or placeholder
variables for which you supply particular values.
monospace
Monospace type indicates commands within a paragraph, URLs, code
in examples, text that appears on the screen, or text that you
enter.
Chapter 1. New Features and Changes
The Unbreakable Enterprise Kernel Release 3 (UEK R3) is Oracle's
third major release of its heavily tested and optimized operating
system kernel for Oracle Linux 6 on the x86-64 architecture. It is
based on the mainline Linux kernel version 3.8.13.
The 3.8.13-26 release is the first quarterly update release for
UEK R3. It includes security and bug fixes, as well as driver
updates.
Oracle actively monitors upstream checkins and applies critical
bug and security fixes to UEK R3.
UEK R3 uses the same versioning model as the mainline Linux kernel
version. It is possible that some applications might not
understand the 3.x versioning scheme. If an application does
require a 2.6 context, you can use the uname26 wrapper command to
start it. However, regular Linux applications are usually neither
aware of nor affected by Linux kernel version numbers.
1.1. Notable Changes
Kdump
* To simplify Kdump configuration, support has been added for
the crashkernel=auto kernel parameter. For Xen, this parameter
is supported only for Domain 0.
Note
If this parameter is enabled, the output of the dmesg command
shows crashkernel=XM@0M. This is normal.
DTrace
* The SDT (Statically Defined Tracing) provider has been
improved so that probes for kernel modules can now be enabled.
Previously you could only enable probes in the core kernel.
Netfilter
* Xtables: IPv4/IPv6 packet logging (xt_LOG) driver updated.
1.2. Xen Improvements
Block Frontend and Backend
* Support for 'indirect-descriptors' allowing more throughput
and lower latency.
* Fixes from kernel versions 3.8 to 3.11.
Network Frontend and Backend
* Support for IPv6 TCP GSO (Generic Segmentation Offload).
* Switch to using NAPI + kthread 1:1 model to provide better
scalability and performance.
* Split of Tx (transmit) and Rx (receive) events.
* Fixes from kernel versions 3.8 to 3.11.
VCPU Hotplug
* Fixes from kernel versions 3.8 to 3.11.
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 Fibre Channel over Ethernet (FCoE) driver
(bnx2fc) updated to 2.4.1e.
* NetXtreme II iSCSI driver (bnx2i) updated to 2.7.8.2b.
Cisco
* Cisco FCoE host bus adapter (HBA) driver (fnic) updated to
1.6.0.8.
Emulex
* OneConnect (previously known as Blade Engine 2) Open-iSCSI
driver (be2iscsi) updated to 10.0.659.0o.
* LightPulse Fibre Channel SCSI (previously known as Fibre
Channel HBA) driver (lpfc) updated to 0:8.3.7.34.4p.
HP
* HP Smart Array CCISS driver (cciss) updated to 4.6.28-22.
* HP Smart Array Controller driver (hpsa) updated to 3.4.2-5.
LSI
* MegaRAID Serial Attached SCSI (SAS) driver (megaraid_sas)
updated to 06.700.06.00-rc1.
Oracle
* Core services module driver (xscore) version 6.0.r7565 added.
Required by all other Oracle Virtual Networking modules.
* Virtual HBA driver (xsvhba) version 6.0.r7565 added.
QLogic
* Fibre Channel HBA driver (qla2xxx) updated to
8.06.00.14.39.0-k.
* iSCSI HBA driver (qla4xxx) updated to 5.04.00.02.06.02-uek3.
1.3.2. Network Adapter Drivers
Broadcom
* NetXtreme II 1 Gigabit network adapter driver (bnx2) updated
to 2.2.4g.
* NetXtreme II 10 Gigabit network adapter driver (bnx2x) updated
to 1.78.80.
* NetXtreme II Converged Network Interface Card core driver
(cnic) updated to 2.5.18c.
* Tigon3 Ethernet adapter driver (tg3) updated to 3.134f.
Emulex
* OneConnect (previously known as Blade Engine 2) 10Gbps adapter
driver (be2net) updated to 4.9.224.0u.
Intel
* PRO/1000 PCI Express Gigabit network adapter driver (e1000e)
updated to 2.5.4-NAPI.
* Gigabit Ethernet network adapter driver (igb) updated to
5.0.6.
* 10 Gigabit PCI Express network adapter driver (ixgbe) updated
to 3.18.7.
* 10 Gigabit PCI Express Virtual Function driver (ixgbevf)
updated to 2.11.3.
Mellanox
* ConnectX Host Channel Adapter (HCA) Ethernet network adapter
driver (mlx4_en) updated to 2.1.8.
* The mlx4_vnic_helper driver has been removed as this
functionality is now included with the mlx4_vnic driver.
Oracle
* Core services module driver (xscore) version 6.0.r7565 added.
Required by all other Oracle Virtual Networking modules.
* Virtual Ethernet driver (xve) version 6.0.r7565 added.
* Virtual NIC driver (xsvnic) version 6.0.r7565 added.
QLogic
* NetXen Multi port (1/10) Gigabit Network Devices driver
(netxen_nic) updated to 4.0.82.
* 1/10 GbE Converged/Intelligent Ethernet Adapter driver
(qlcnic) updated to 5.3.52.3.
1.3.3. Miscellaneous Drivers
HP
* HP ProLiant Channel Interface Device Driver for Integrated
Lights-Out (hpilo) updated to 1.4.1.
1.4. Technology Preview
The following features included in the Unbreakable Enterprise
Kernel Release 3 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.
* Transcendent memory
Transcendent Memory (tmem) 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 3 and no re-certifications are needed
for RHEL certified applications.
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. The kernel ABI
for UEK R3 will remain unchanged in all subsequent updates to the
initial release. In this release, there are changes to the kernel
ABI relative to UEK R2 that require recompilation of third-party
kernel modules on the system. Before installing UEK R3, verify its
support status with your application vendor.
Chapter 2. Fixed and Known Issues
This chapter describes the fixed and known issues for the
Unbreakable Enterprise Kernel Release 3.
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
The following issues have been fixed in this update.
btrfs
* The usage message for the -c option to the btrfs qgroup limit
command has been updated to make it clear that the quota limit
is always enforced after compression and it is not possible to
turn off this option. (Bug ID 16557528)
* The btrfs receive command no longer causes an error when you
retrieve data containing subvolumes. (Bug ID 17661845)
* When you create a subdirectory in a directory that has the
default ACLs (access control lists), the newly created
subdirectory did not inherit the defaults from the parent. The
ACLs are now applied correctly. (Bug ID 17669341)
* Several performance and stability fixes. (Bug ID 17790692)
* Due to the copy-on-write design of btrfs, snapshots can share
the same data blocks. In UEK R3, sharing could be broken by
defragmentation. This has been fixed. (Bug ID 18098511)
CIFS
* Support for SMB2 has been enabled in UEK R3. (Bug ID 17486287)
DTrace
* The vtimestamp() function now works correctly. The function
keeps track of how much time a task has spent actually
processing on a CPU. (Bug ID 17741477)
* The SDT (Statically Defined Tracing) provider has been
improved so that probes for kernel modules can now be enabled.
Previously you could only enable probes in the core kernel.
(Bug ID 17851716)
* The dev_statname and dev_pathname in the devinfo_t structure
now contains the correct information when the device is not
partitioned. (Bug ID 17973698)
ext4
* If an ext4 file system is full, preallocated space may not be
writeable. (Bug ID 17347111)
I/O
* The io_submit call is slow because it flushes writes. (Bug ID
14548775)
NFS
* On an NFSv4 mount with delegations enabled, a file opened as
RDWR and as RDONLY by several clients could cause a kernel
crash when the state recovery process begins. (Bug ID
17931281)
OCFS2
* The default coherency mount option is now buffered for better
performance with direct I/O writes. Previously it was full.
(Bug ID 17988729)
XFS
* New files and directories created under the original directory
now correctly inherit the group from the SGID group. (Bug ID
17354234)
xen
* The race condition between dentry put and lookup in configfs
is fixed. (Bug ID 17931342)
2.2. Known Issues
This section describes the known issues in this update.
ACPI
* On 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)
* The following messages indicate that the BIOS does not present
a suitable interface, such as _PSS or _PPC, that the
acpi-cpufreq module requires:
kernel: powernow-k8: this CPU is not supported anymore, using acpi-cp
ufreq instead.
modprobe: FATAL: Error inserting acpi_cpufreq
There is no known workaround for this error. (Bug ID 17034535)
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
* 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. (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. (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)
* 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)
* 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.
* 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. Although the limitation of the number of hard links
in a single directory has been increased to 65535, the version
of mkfs.btrfs that is provided in the btrfs-progs package does
not yet support the compatibility flag for this feature. (Bug
ID 16285431)
* 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. (Bug ID 16569350)
* When you overwrite data in a file, starting somewhere in the
middle of the file, the overwritten space is counted twice in
the space usage numbers that btrfs qgroup show displays. (Bug
ID 16609467)
* If you run btrfsck --init-csum-tree on a file system and then
run a simple btrfsck on the same file system, the command
displays a Backref mismatch error that was not previously
present. (Bug ID 16972799)
* Btrfs tracks the devices on which you create btrfs file
systems. If you subsequently reuse these devices in a file
system other than btrfs, you might see error messages such as
the following when performing a device scan or creating a
RAID-1 file system, for example:
ERROR: device scan failed '/dev/cciss/c0d0p1' - Invalid argument
You can safely ignore these errors. (Bug ID 17087097)
* If you use the -s option to specify a sector size to
mkfs.btrfs that is different from the page size, the created
file system cannot be mounted. By default, the sector size is
set to be the same as the page size. (Bug ID 17087232)
* In some cases, it is possible to run the btrfs-convert command
on a mounted file system. This may result in unexpected
behaviour and can possibly cause a kernel panic. Make sure to
unmount a file system before converting it to Btrfs. (Bug ID
18061751)
* The btrfs subvolume delete command may result in a "Directory
not empty" error. This error message is incorrect. The actual
reason that the subvolume cannot be deleted is that the
subvolume is configured as the default subvolume. The default
subvolume is the subvolume that is mounted when no subvolume
is specified with the mount command. Before you can delete the
subvolume, you need to configure a different default subvolume
using the btrfs subvolume set-default command. (Bug ID
17661944)
CPU Microcode Update Failures on PVM or PVHVM Guests
When running Oracle Linux 6 with UEK R3, 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)
dm-nfs Module Obsolete
In UEK R2, the dm-nfs module provided the ability to create a
loopback device for a mounted NFS file or file system. For
example, the feature allowed you to create the shared storage for
an Oracle 3 VM cluster on an NFS file system. The dm-nfs module
provided direct I/O to the server and bypassed the loop driver to
avoid an additional level of page caching. The dm-nfs module is
not provided with UEK R3. The loop driver can now provide the same
I/O functionality as dm-nfs by extending the AIO interface to
perform direct I/O. To create the loopback device, use the losetup
command instead of dmsetup.
DTrace
* Using kill -9 to terminate dtrace can leave breakpoints
outstanding in processes being traced, which might sooner or
later kill them.
* Argument declarations for probe definitions cannot be declared
with derived types such as enum, struct, or union.
* The following compiler warning can be ignored for probe
definition arguments of type string (which is a D type but not
a C type):
provider_def.h:line#: warning: parameter names (without types) in fun
ction declaration
ERST Message
You can safely ignore the following message that might be
displayed in syslog or dmesg:
ERST: Failed to get Error Log Address Range.
The message indicates that the system BIOS does not support an
Error Record Serialization Table (ERST). (Bug ID 17034576)
ext4 Inline Data
The inline data feature that allows the data of small files to be
stored inside their inodes is not yet available. The -O
inline_data option to the mkfs.ext4 and tune2fs commands is not
supported. (Bug ID 17210654)
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)
Huge Pages
One-gigabyte (1 GB) huge pages are not currently supported for the
following configurations:
* HVM guests
* PV guests
* Oracle Database
Two-megabyte (2 MB) huge pages have been tested and work with
these configurations.
(Bug ID 17299364, 17299871, 17271305)
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.
ioapic Failure Messages
You can safely ignore messages such as ioapic: probe of
0000:00:05.4 failed with error -22. Such messages are the result
of the ioapic driver attempting to re-register I/O APIC PCI
devices that were already registered at boot time. (Bug ID
17034993)
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)
IPoIB Mode Switching
The Internet Protocol over InfiniBand (IPoIB) driver supports the
use of either connected mode or datagram mode with an interface,
where datagram mode is the default mode. Changing the mode of an
InfiniBand interface by echoing either connected or datagram to
/sys/class/net/ibN/mode is not supported. It is also not possible
to change the mode of an InfiniBand interface while it is enabled.
To change the IPoIB mode of an InfiniBand interface:
1. Edit the /etc/sysconfig/network-scripts/ifcfg-ibN
configuration file, where N is the number of the interface:
+ To configure connected mode, specify CONNECTED_MODE=yes
in the file.
+ To configure datagram mode, either specify
CONNECTED_MODE=no in the file or do not specify this
setting at all (datagram mode is enabled by default).
Note
Before saving your changes, make sure that you have not
specified more than one setting for CONNECTED_MODE in the
file.
2. To enable the specified mode on the interface, use the
following commands to take down the interface and bring it
back up:
# ifdown ibN
# ifup ibN
(Bug ID 17479833)
Linux Containers (LXC)
* The correct operation of containers might require that you
completely disable SELinux on the host system. For example,
SELinux can interfere with container operation under the
following conditions:
+ Running the halt or shutdown command from inside the
container hangs the container or results in a permission
denied error. (An alternate workaround is to use the init
0 command from inside the container to shut it down.)
+ Setting a password inside the container results in a
permission denied error, even when run as root.
+ You want to allow ssh logins to the container.
To disable SELinux on the host:
1. Edit the configuration file for SELinux,
/etc/selinux/config and set the value of the SELINUX
directive to disabled.
2. Shut down and reboot the host system.
* The root user in a container can affect the configuration of
the host system by setting some /proc entries. (Bug ID
17190287)
* Using yum to update packages inside the container that use
init scripts can undo changes made by the Oracle template.
* Migrating live containers (lxc-checkpoint) is not yet
supported.
* Oracle Database is not yet supported for use with Linux
Containers. The following information is intended for those
who want to experiment with such a configuration.
The following /proc parameter files may only be set on the
host and not for individual containers:
+ /proc/sys/fs/aio-max-nr
+ /proc/sys/net/core/rmem_default
+ /proc/sys/net/core/rmem_max
+ /proc/sys/net/core/wmem_default
+ /proc/sys/net/core/wmem_max
+ /proc/sys/net/ipv4/ip_local_port_range
Setting the parameters in the host to the Oracle recommended
values sets them for all containers and allows the Oracle
database to run in a container. For more information, see
Configuring Kernel Parameters
(http://docs.oracle.com/cd/E11882_01/install.112/e24326/toc.ht
m#BHCCADGD). (Bug ID 17217854)
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)
Power/Level is Deprecated Message (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 R3 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)
RDMA Does Not Load the mlx4_ib Module
If you enable the OFED stack and the RDMA service but the version
of the RDMA package is lower than rdma‑3.10‑3.0.2.el6, the RDMA
service does not load the mlx4_ib module automatically.
To configure the RDMA service to load the mlx4_ib module at boot
time:
1. Edit /etc/rdma/rdma.conf and set the entry MLX4_LOAD=yes in
this file.
2. To make the change take effect, restart the RDMA service or
reboot the system.
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.
Slow Performance With Multipath Devices
Starting with UEK R2, the device mapper has had the capability to
check whether the underlying storage device has advertised the
need to flush the data that resides in the device's cache to its
non-volatile storage. For a data integrity operation, such as
fsync and sync, the operation will now need to include the time to
flush the device's cache (if it is advertised). Such an operation
will appear to be slower when compared to a previous older kernel,
however this is the correct behavior. (Bug ID 17823743)
Soft Lockup Errors When Booting
When upgrading or installing the UEK R3 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)
Transparent Huge Pages
This release removes the Transparent Huge Pages (THP) feature.
Following extensive benchmarking and testing, Oracle found that
THP caused a performance degradation of between 5 and 10% for some
workloads. 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 UEK release, 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 16823432)
User Namespaces
The kernel functionality (CONFIG_USER_NS) that allows unprivileged
processes to create namespaces for users inside which they have
root privileges is not currently implemented because of a clash
with the implementation of XFS. This functionality is primarily
intended for use with Linux Containers. As a result, the
lxc-checkconfig command displays User namespace: missing. (Bug ID
16656850)
Virtualization
* When booting UEK R3 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 R3 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)
* On virtualized systems that are built on Xen version 3,
including all releases of Oracle VM 2 including 2.2.2 and
2.2.3, disk synchronization requests for ext3 and ext4 file
systems result in journal corruption with kernel messages
similar to the following being logged:
blkfront: barrier: empty write xvda op failed
blkfront: xvda: barrier or flush: disabled
In addition, journal failures such as the following might be
reported:
Aborting journal on device xvda1
The workaround is to add the mount option barrier=0 to all
ext3 and ext4 file systems in the guest VM before upgrading to
UEK R3. For example, you would change a mount entry such as:
UUID=4e4287b1-87dc-47a8-b69a-075c7579eaf1 / ext3 defaults 1 1
so that it reads:
UUID=4e4287b1-87dc-47a8-b69a-075c7579eaf1 / ext3 defaults,barrier=
0 1 1
This issue does not apply to Xen 4 based systems, such as
Oracle VM 3. (Bug ID 17310816)
X.509 Certificates for Module Verification
The system reports a message similar to the following if there is
a problem loading an in-kernel X.509 module verification
certificate at boot time:
Loading module verification certificates
X.509: Cert 0c21da3d73dcdbaffc799e3d26f3c846a3afdc43 is not yet valid
MODSIGN: Problem loading in-kernel X.509 certificate (-129)
This error occurs because the hardware clock lags behind the
system time as shown by hwclock, for example:
# hwclock
Tue 20 Aug 2013 01:41:40 PM EDT -0.767004 seconds
The solution is to set the hardware clock from the system time by
running the following command:
# hwclock --systohc
After correcting the hardware clock, no error should be seen at
boot time, for example:
Loading module verification certificates
MODSIGN: Loaded cert 'Slarti: Josteldalsbreen signing key:
0c21da3d73dcdbaffc799e3d26f3c846a3afdc43'
(Bug ID 17346862)
Chapter 3. Installation and Availability
You can install Unbreakable Enterprise Kernel Release 3 (UEK R3)
on Oracle Linux 6 Update 4 or newer, 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.
UEK R3 is supported on the x86-64 architecture but not on x86.
The kernel's source code is available via a public git source code
repository at https://oss.oracle.com/git/?p=linux-uek3-3.8.git.
Starting with Oracle Linux 6 Update 5 for x86-64, UEK R3 is the
default boot kernel for fresh installations of Oracle Linux.
For systems that are running UEK R3 and are subscribed to the
ol6_x86_64_UEKR3_latest channel on ULN, or the ol6_UEKR3_latest
repository in the Oracle Public Yum repository, you upgrade to the
latest UEK release as follows:
1. Upgrade all packages on the system, including kernel packages.
# yum update
By default, the boot manager automatically enables the most
recent kernel version so you do not need to change your GRUB
configuration.
2. Reboot the system.
# shutdown -r now
For systems that are currently running a previous version of the
Unbreakable Enterprise Kernel (UEK R2) or the Red Hat compatible
kernel (RHCK), you can switch to UEK R3 at any time. For details,
see:
* Section 3.1, "Switching a System to UEK R3 (ULN)"
* Section 3.2, "Switching a System to UEK R3 (Public Yum)"
3.1. Switching a System to UEK R3 (ULN)
If you have a subscription to Oracle Unbreakable Linux support,
you can obtain the packages for Unbreakable Enterprise Kernel
Release 3 (UEK R3) by registering your system with the Unbreakable
Linux Network (ULN) and subscribing it to additional channels.
Before you begin:
* Ensure the system is registered with ULN.
For information about registering with ULN, see the Oracle
Linux Unbreakable Linux Network User's Guide
(http://docs.oracle.com/cd/E37670_01/E39381/html/index.html).
* Check that the system meets the requirements for installing
UEK R3.
For details, see Chapter 3, "Installation and Availability."
* Remove some of the existing OpenFabrics Enterprise
Distribution (OFED) packages.
You only need to do this if you have installed any OFED
packages on your system and you want to replace them with the
latest OFED tools packages. The packages have to be removed
manually, see Section 3.3, "Upgrading OFED Packages."
To Switch a System to UEK R3:
1. Using a browser, log in at http://linux.oracle.com with the
ULN user name and password that you used to register the
system.
2. On the Systems tab, click the link named of your system in the
list of registered machines.
3. On the System Details page, click Manage Subscriptions.
4. On the System Summary page, select each required channel in
the Available Channels list and click the right arrow to move
the channel to the Subscribed Channels list.
The kernel image and user-space packages are available on the
following ULN channels:
Channel Name
Description and Channel Label
Oracle Linux 6 Latest (x86_64)
All packages released for Oracle Linux 6 (x86_64) including the
latest errata packages. (x86_64).
(ol6_x86_64_latest)
Unbreakable Enterprise Kernel Release 3 for Oracle Linux 6
(x86_64) - Latest
Latest packages for Unbreakable Enterprise Kernel Release 3 for
Oracle Linux 6 (x86_64).
Contains the kernel-uek*, dtrace-modules-*, libdtrace-*, and
uname26 packages.
(ol6_x86_64_UEKR3_latest)
Oracle Linux 6 Dtrace Userspace Tools (x86_64) - Latest
The latest DTrace userspace tools for Oracle Linux 6 (x86_64).
Contains the dtrace-utils* packages.
(ol6_x86_64_Dtrace_userspace_latest)
OFED supporting tool packages for Unbreakable Enterprise Kernel on
Oracle Linux 6 (x86_64)
Latest OpenFabrics Enterprise Distribution (OFED) supporting tools
for the Unbreakable Enterprise Kernel (UEK) on Oracle Linux 6
(x86_64).
(ol6_x86_64_ofed_UEK)
HA Utilities for MySQL and Oracle Linux 6 (x86_64)
Management Utilities for MySQL HA with Oracle Linux 6.
Contains the drbd84-utils package.
(ol6_x86_64_mysql-ha-utils)
As a minimum, you should subscribe the system to the
ol6_x86_64_latest and the ol6_x86_64_UEKR3_latest channels. If
required, you can also add the channels for the DTrace, OFED,
and DRBD packages.
Caution
Take care not to select the ol6_x86_64_UEK_BETA channel.
Because you are switching to the latest UEK kernel, you no
longer need to subscribe the system to the previous UEK R2
(ol6_x86_64_UEK_latest) channel.
5. When you have finished selecting channels, click Save
Subscriptions and log out of ULN.
6. Log in as root on the system.
7. Upgrade all packages on the system, including kernel packages.
# yum update
By default, the boot manager automatically enables the most
recent kernel version so you do not need to change your GRUB
configuration.
8. Reboot the system.
# shutdown -r now
3.2. Switching a System to UEK R3 (Public Yum)
If your system is not registered with ULN, you can obtain most of
the packages for Unbreakable Enterprise Kernel Release 3 (UEK R3)
from Oracle Public Yum by subscribing it to additional
repositories.
Before you begin:
* Check that the system meets the requirements for installing
UEK R3.
For details, see Chapter 3, "Installation and Availability."
* Remove some of the existing OpenFabrics Enterprise
Distribution (OFED) packages.
You only need to do this if you have installed any OFED
packages on your system and you want to replace them with the
latest OFED tools packages. The packages have to be removed
manually, see Section 3.3, "Upgrading OFED Packages."
To Switch a System to UEK R3:
1. Log in as root on the system.
2. Change directory to /etc/yum.repos.d.
# cd /etc/yum.repos.d
Note
This assumes that yum on your system is configured to find
repository files in the default /etc/yum.repos.d directory.
3. Download the Oracle Linux 6 repository configuration file,
http://public-yum.oracle.com/public-yum-ol6.repo.
For example:
# wget http://public-yum.oracle.com/public-yum-ol6.repo
The /etc/yum.repos.d directory is updated with the repository
configuration file.
4. Enable the required repositories by editing the
public-yum-ol6.repo file.
You enable or disable repositories in the file by setting the
value of the enabled directive to 1 or 0 as required.
The kernel image and user-space packages are available on the
following Oracle Public Yum repositories:
Channel Label
Description
ol6_latest
All packages released for Oracle Linux 6 (x86_64) including the
latest errata packages.
ol6_UEKR3_latest
Latest packages for Unbreakable Enterprise Kernel Release 3 for
Oracle Linux 6.
Contains the kernel-uek*, dtrace-modules-*, libdtrace-*, and
uname26 packages.
ol6_ofed_UEK
Latest OpenFabrics Enterprise Distribution (OFED) supporting tools
for the Unbreakable Enterprise Kernel (UEK) on Oracle Linux 6
(x86_64).
As a minimum, you should enable the ol6_latest and the
ol6_UEKR3_latest repositories.
Note
The DTrace utility and DRBD packages are not available on
Public Yum.
Because you are switching to the latest UEK kernel, you can
disable the previous UEK R2 (ol6_UEK_latest) repository.
In the following example, the ol6_UEKR3_latest repository is
enabled, and the ol6_UEK_latest repository is disabled:
[ol6_UEKR3_latest]
name=Latest Unbreakable Enterprise Kernel for Oracle Linux $releaseve
r ($basearch)
baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL6/UEKR3/lates
t/$basearch/
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-oracle
gpgcheck=1
enabled=1
[ol6_UEK_latest]
name=Latest Unbreakable Enterprise Kernel for Oracle Linux $releaseve
r ($basearch)
baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL6/UEK/latest/
$basearch/
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-oracle
gpgcheck=1
enabled=0
5. Upgrade all packages on the system, including kernel packages.
# yum update
By default, the boot manager automatically enables the most
recent kernel version so you do not need to change your GRUB
configuration.
6. Reboot the system.
# shutdown -r now
3.3. Upgrading OFED Packages
If you have enabled the ol6_ofed_UEK channel, you must remove any
existing OFED packages for the 32-bit x86 architecture before you
can upgrade the remaining OFED packages on your system. You must
also completely remove and reinstall the ibutils packages. The
latest version of the ibutils package no longer depends on an
ibutils-libs package as the libraries are now included in ibutils
itself.
Use the following command to remove any non-upgradable packages
for the x86 architecture:
# rpm -e infiniband-diags-1.5.12-5.el6.i686 \
libibcm-1.0.5-3.el6.i686 \
libibcm-devel-1.0.5-3.el6.i686 \
libibmad-1.3.9-1.el6.i686 \
libibmad-devel-1.3.9-1.el6.i686 \
libibumad-1.3.8-1.el6.i686 \
libibumad-devel-1.3.8-1.el6.i686 \
libibverbs-1.1.6-5.el6.i686 \
libibverbs-devel-1.1.6-5.el6.i686 \
libmlx4-1.0.4-1.el6.i686 \
librdmacm-1.0.17-0.git4b5c1aa.el6.i686 \
librdmacm-devel-1.0.17-0.git4b5c1aa.el6.i686 \
opensm-devel-3.3.15-1.el6.i686 \
opensm-libs-3.3.15-1.el6.i686 \
ibacm-devel-1.0.8-0.git7a3adb7.el6.i686
Use the following commands to remove the existing ibutils and
ibutils-libs packages and install the new ibutils package:
# rpm -e ibutils-1.5.7-7.el6.x86_64 \
ibutils-libs-1.5.7-7.el6.x86_64
# yum install ibutils
Copyright (c) 2014, Oracle and/or its affiliates. All rights
reserved. Legal Notices