User`s guide

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 3.8.13-16 release also updates drivers and includes bug and security fixes.

Oracle actively monitors upstream checkins and applies critical bug and security fixes to UEK3.

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

The following sections describe the major new features of Unbreakable Enterprise Kernel Release 3 (UEK

R3) relative to UEK R2. If applicable, the mainline version in which a feature was introduced is noted in

parentheses.

For brief summaries of other changes, see Appendix A, Other Changes.

1.1.1 Architecture

• Support for the Intel IVB processor family has been added.

• The efivars module provides an area of firmware-managed, nonvolatile storage, which can be used

as a persistent storage backend to maintain copies of kernel oopses and aid the diagnosis of problems.

(3.1)

1.1.2 Control Groups and Linux Containers

Control groups (cgroups) and Linux Containers (LXC) are now supported features. LXC is supported for

64-bit hosts, but not 32-bit hosts (in any case, UEK R3 is not available for the 32-bit x86 architecture). Both

32-bit and 64-bit guest containers can be configured. However, some applications might not be supported

for use with these features.

• The cgroups feature allows you to manage access to system resources by processes. For more

information, see Control Groups.

• LXC is based on the cgroups and namespaces 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. For more information, see Linux Containers.

The lxc-attach command is supported by UEK R3 with the lxc-0.9.0-2.0.4 package. lxc-

attach allows you to execute an arbitrary command inside a running container from outside the

container. For more information, see the lxc-attach(1) manual page.

Note

To access this feature, use yum update to install the lxc-0.9.0-2.0.4

package (or later version of this package).