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  • June 21, 2018

Announcing the general availability of the Unbreakable Enterprise Kernel Release 5

Avi Miller
Senior Solutions Architect

The Unbreakable Enterprise Kernel Release 5 (UEK R5) is a heavily tested and optimized operating system kernel for Oracle Linux 7 Update 5 and later on 64-bit Intel (x86_64) and ARM (aarch64) architectures. It is based on the mainline Linux kernel version 4.14 LTS. This release also updates drivers and includes bug and security fixes.

Introduction of 64-bit ARM (aarch64) architecture

Oracle Linux with UEK R5 delivers kernel modifications to enable support for 64-bit ARM (aarch64) architecture. These changes are built and tested against existing ARM hardware and provide the initial groundwork to support Oracle Linux for ARM. Any ARM features available in UEK R5 are released as a technical preview and some limitations of functionality apply.

The Oracle Linux 7 for ARM release includes a toolchain that includes version 7.3 of the gcc compiler and provides a solid developer toolset to build code for 64-bit ARM platforms. The UEK R5 for the ARM platform is built using this toolchain.

Notable Changes

  • Secure boot improvements. Secure boot is designed to protect a system against malicious code being loaded and executed early in the boot process. Secured platforms load only software binaries, such as option ROM drivers, boot loaders, and operating system loaders, that are unmodified and trusted by the platform. While the operating system is loaded, measures have been added to prevent malicious code from being injected on subsequent boots.
  • NUMA balancing enabled.  Improvements and fixes to NUMA balancing help resolve issues that could cause high I/O wait times when this feature was enabled. NUMA balancing is automatically enabled on systems that have multiple NUMA nodes. 
  • RoCE support.  RDMA over Converged Ethernet (RoCE), a standard InfiniBand Trade Association (IBTA) protocol enables efficient data transfer for RDMA over Ethernet networks using UDP encapsulation to transcend Layer 3 networks.
  • TCP-BBR enabled.  TCP-BBR, a feature that can be used to achieve higher bandwidth and lower latency for internet traffic can offer significant performance improvements for internet-based applications. BBR (Bottleneck Bandwidth and Round-Trip Time) is a scheduling algorithm that helps to control the transmit rate of the TCP protocol to reduce buffering by monitoring round-trip times against bandwidth bottlenecks to reduce TCP congestion.

Notable Driver Updates

  • Hyper-V drivers updated.  The Hyper-V storage driver, hv_storvsc, has been updated to provide performance improvements for I/O operations on certain workloads by eliminating bounce buffers. The Hyper-V network driver, hv_netvsc, has been updated to support transparent SR-IOV on Virtual Function devices to reduce configuration complexity and the use of a dedicated bonding driver and script to handle hot plugging of the required PCI devices.
  • Intel iWARP RDMA driver added.  The Intel Ethernet Connection X722 iWARP RDMA Driver, i40iw, has been added to the driver modules included in this kernel release. A library, libi40iw, has been added for direct userspace use of this RDMA hardware.
  • Amazon Elastic Network Adapter Driver Updated.  The Elastic Network Adapter Driver, ena, has been updated to version 1.5.0k. This version provides a number of upstream bug fixes and improvements. Other features include additional power management operations, initial support for IPv6 RSS, and improved driver robustness.

For more details on these and other new features and changes, including a full list of CVEs fixed in this release, please consult the UEK R5 Release Notes.

Certification of Oracle products

Before updating an Oracle Linux system to UEK R5, please confirm your applications, including Oracle applications, are supported with UEK R5. Certification of Oracle products on Oracle Linux with the UEK R5 is determined by each Oracle product group. You may find additional information on https://support.oracle.com/epmos/faces/CertifyHome.

Oracle Automatic Storage Management Cluster File System (Oracle ACFS) certification for different kernel versions is described in Document ID 1369107.1 on My Oracle Support.


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 UEK R5 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 R5 remains unchanged in all subsequent updates to the initial release. In this release, there are changes to the kernel ABI relative to previous releases that require recompilation of third-party kernel modules on the system. Before installing UEK R5, verify its support status with your application vendor.

Supported Upgrade Path

Customers can upgrade existing Oracle Linux 7 servers using either the Unbreakable Linux Network or the Oracle Linux yum server.

Software Download

Oracle Linux can be downloaded, used and distributed free of charge and updates and errata are freely available. This allows you to decide which of your systems require a support subscription and makes Oracle Linux an ideal choice for your development, testing and production systems. You decide which support coverage is the best for each of your systems, individually, while keeping all of your systems up-to-date and secure. For customers with Oracle Linux Premier Support, you also receive access to zero-downtime kernel updates using Oracle Ksplice and support for Oracle OpenStack.

UEK R5 Availability in Oracle Cloud Infrastructure

Oracle Linux images available on Oracle Cloud Infrastructure are frequently updated to help ensure access to the latest software. Oracle provided images in Oracle Cloud Infrastructure will soon include Oracle Linux 7 Update 5 with UEK Release 5.

Oracle Linux Premier Support is included with your Oracle Cloud Infrastructure subscription at no additional cost.  You can take advantage of all the benefits Oracle Linux Support provides, including access to the latest packages and updates, 24x7 expert support, the My Oracle Support portal with an extensive Linux knowledge base, Oracle Ksplice zero-downtime updates, and the use of Oracle Enterprise Manager to manage and monitor Oracle Linux instances. Using Oracle Linux on Oracle Cloud Infrastructure enables you to have a single point of contact for support across cloud infrastructure, OS, and Oracle software.

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