1. Release Notes for Oracle Linux 8.5
  2. About Oracle Linux 8

1 About Oracle Linux 8

The current Oracle Linux 8 release contains new features and enhancements that improve performance in different areas including automation and management, security and compliance, container management, and developer tools. These enhancements are especially designed to make the operating system adaptable to different types of deployment from strictly on-premises installations, hybrid deployments that combine on-premises and cloud installations, and full cloud deployment.

System Requirements and Limitations

To determine whether your hardware is supported on the current Oracle Linux 8 release, check the Hardware Certification List at https://linux.oracle.com/hardware-certifications. Note that hardware is listed as it becomes available and is validated.

Note that Oracle Linux 8 for the aarch64 platform is primarily engineered for use with Ampere™ eMAG™-based EVK platform and the Marvell ThunderX2® processor. Other hardware may be supported and added to the Hardware Certification List in future.

CPU, memory, disk and file system limits for all Oracle Linux releases are described in Oracle Linux: Limits.

Available Architectures

The release is available on the following platforms:

  • Intel 64-bit (x86_64)

  • AMD 64-bit (x86_64)

  • 64-bit Arm (aarch64)

The Arm platform is only supported with Unbreakable Enterprise Kernel Release (UEK).

Shipped Kernels

For the x86_64 platform, Oracle Linux 8.5 ships with the following default kernel packages:

  • kernel-4.18.0-348.el8: (Red Hat Compatible Kernel (RHCK))

  • kernel-uek-5.4.17-2136.300.7.el8uek: (Unbreakable Enterprise Kernel Release 6 (UEK R6))

    For new installations, the UEK kernel is automatically enabled and installed. It also becomes the default kernel on first boot.

    Starting with the Oracle Linux 8.5 release, Unbreakable Enterprise Kernel Release 7 (UEK R7) is also available as an additional installation option.

Note:

For the 64-bit Arm (aarch64) platform, Oracle Linux ships only with the UEK kernel.

The Oracle Linux release is tested as a bundle, as shipped on the installation media image. When installed from the installation media image, the kernel's version included in the image is the minimum version that is supported. Downgrading kernel packages is not supported, unless recommended by Oracle Support.

About the Unbreakable Enterprise Kernel

The Unbreakable Enterprise Kernel (UEK) is a Linux kernel built by Oracle and supported through Oracle Linux support. UEK is tested on Arm (aarch64), Intel x86, and AMD x86 (x86_64) platforms. Each release contains additional features, bug fixes, and updated drivers to provide support for key functional requirements, improve performance, and optimize the kernel for use on Oracle products such as Oracle's Engineered Systems, Oracle Cloud Infrastructure, and large enterprise deployments for Oracle customers.

Typically, a UEK release contains changes to the kernel ABI relative to a previous UEK release. These changes require recompilation of third-party kernel modules on the system. To minimize impact on interoperability during releases, the Oracle Linux team works closely with third-party vendors regarding hardware and software that have dependencies on kernel modules. Thus, before installing the latest UEK release, verify its support status with your application vendor.

The kernel ABI for a UEK release remains unchanged in all subsequent updates to the initial release.

The kernel source code for UEK is available after the initial release through a public git source code repository at https://github.com/oracle/linux-uek.

For more information about UEK such as tutorials, notices, and release notes of different UEK versions, go to Unbreakable Enterprise Kernel documentation.

User Space Compatibility

Oracle Linux maintains user space compatibility with Red Hat Enterprise Linux (RHEL) that is independent of the kernel version that underlies the operating system. Existing applications in user space continue to run unmodified on UEK R6 and UEK R7, with no required recertifications for RHEL certified applications.

Obtaining Installation Images

The following installation images for the current Oracle Linux 8 release are available:

  • Full ISO of Oracle Linux for typical on-premise installations

  • Boot ISO of Oracle Linux for network installations

  • Boot ISO of the supported UEK release for installing on hardware that is supported only on UEK

  • Source DVDs

You can download these images from the following locations. Note that the images in these locations are for both the x86_64 and aarch64 platforms, unless indicated otherwise:

To prepare a downloaded image for installing Oracle Linux, see Oracle Linux 8: Installing Oracle Linux.

For information about the available ISOs for the three most recent updates to the Oracle Linux releases, refer to https://yum.oracle.com/oracle-linux-isos.html.

For developers who are making use of the Raspberry Pi hardware platform, Oracle provides an unsupported developer release image, which includes the firmware that is required to boot this platform. For more information about making use of the Raspberry Pi hardware platform, see Install Oracle Linux on a Raspberry Pi.

Note:

Aside from installation ISOs, you can also use Oracle Linux images to create compute instances on Oracle Cloud Infrastructure. For information about these images, see the release notes for the specific image that you are using on the Oracle Cloud Infrastructure Documentation page.

To use Oracle Linux on Oracle Cloud Infrastructure, see https://docs.oracle.com/iaas/oracle-linux/home.htm.

Upgrading From Oracle Linux 7 to Oracle Linux 8

You can upgrade an Oracle Linux 7 system to the latest Oracle Linux 8 release by using the leapp utility. For step-by-step instructions, as well as information about any known issues that you might encounter when upgrading your system, see Oracle Linux 8: Performing System Upgrades With Leapp.

Installing Oracle-Supported RDMA Packages

Oracle Linux 8 releases earlier than Oracle Linux 8.7 ship with UEK R6 as the default kernel.

Starting with Oracle Linux 8.5, you also have the option of installing UEK R7. From Oracle Linux 8.7 onward, UEK R7 is the default kernel.

Oracle provides Remote Direct Memory Access (RDMA) packages for use with UEK R6 and UEK R7. The RDMA feature enables direct memory access between two systems that are connected by a network. RDMA facilitates high-throughput and low-latency networking in clusters.

To use RDMA features, you must first install the Oracle-supported RDMA packages. To do so, ensure that your system is subscribed to the appropriate channels on ULN or that you have enabled the appropriate repositories on the Oracle Linux yum server.

RDMA With UEK R6

If you are subscribed to ULN, enable the following channels:

  • ol8_x86_64_UEKR6

  • ol8_x86_64_baseos_latest

  • ol8_x86_64_appstream

  • ol8_x86_64_UEKR6_RDMA

Note that if your system is newly registered on ULN, it is already subscribed to the ol8_x86_64_UEKR6, ol8_x86_64_baseos_latest, and ol8_x86_64_appstream channels by default. However, you must explicitly subscribe to the ol8_x86_64_UEKR6_RDMA channel prior to installing RDMA packages.

If you are using the Oracle Linux yum server, enable the following repositories:

  • ol8_UEKR6

  • ol8_baseos_latest

  • ol8_appstream

  • ol8_UEKR6_RDMA

Note that if your system already uses the Oracle Linux yum server, the ol8_UEKR6, ol8_baseos_latest, and ol8_appstream repositories are enabled by default. However, you must explicitly enable the ol8_UEKR6_RDMA repository prior to installing RDMA packages.

For additional information about RDMA, including any known issues, see Unbreakable Enterprise Kernel: Release Notes for Unbreakable Enterprise Kernel Release 6 Update 3.

RDMA With UEK R7

If you are subscribed to ULN, enable the following channels:

  • ol8_x86_64_UEKR7

  • ol8_x86_64_baseos_latest

  • ol8_x86_64_appstream

  • ol8_x86_64_UEKR7_RDMA

Note that if your system is newly registered on ULN, it is already subscribed to the ol8_x86_64_UEKR6, ol8_x86_64_baseos_latest, and ol8_x86_64_appstream channels by default. You should disable ol8_x86_64_UEKR6 and then explicitly subscribe to the ol8_x86_64_UEKR7_RDMA and ol8_x86_64_UEKR7_RDMA channels prior to installing RDMA packages.

If you are using the Oracle Linux yum server, enable the following repositories:

  • ol8_UEKR7

  • ol8_baseos_latest

  • ol8_appstream

  • ol8_UEKR7_RDMA

Note that if your system already uses the Oracle Linux yum server, the ol8_UEKR6, ol8_baseos_latest, and ol8_appstream repositories are enabled by default. You should disable ol8_UEKR6 and then explicitly subscribe to the ol8_UEKR7_RDMA and ol8_UEKR7_RDMA repositories prior to installing RDMA packages.

For additional information about RDMA, including any known issues, see Unbreakable Enterprise Kernel: Release Notes for Unbreakable Enterprise Kernel Release 7.