1. Release Notes for Oracle Linux 8.9
  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 OS adaptable to different types of deployment such as on-premises installations, hybrid deployments that combine on-premises and cloud installations, and full cloud deployment.

Important:

Upgrading from an Oracle Linux Developer Preview release to its later official version isn't supported. If you're running the Developer Preview version, you must reinstall the official Oracle Linux release upon its general availability.

System Requirements and Limitations

To check whether a specific hardware can be used with the current Oracle Linux 8 release, see the Hardware Certification List at https://linux.oracle.com/hardware-certifications. Note that as hardware becomes available and validated, the hardware is added to the list.

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 might be supported and added to the Hardware Certification List in the 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)

  • Arm 64-bit (aarch64)

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

Shipped Kernels

On the x86_64 platform, the current Oracle Linux 8 release ships with the following default kernel packages:

  • 4.18.0-513.5.1 (Red Hat Compatible Kernel (RHCK))

  • 5.15.0-200.131.27 (Unbreakable Enterprise Kernel Release 7 Update 2 (UEK R7U2))

    For new installations, the UEK R7 is automatically enabled and installed. It also becomes the default kernel on first boot.

    On the aarch64 platform, Oracle Linux ships with the UEK kernel only.

    Important:

    If you're upgrading from a previous Oracle Linux 8 version, the kernel isn't automatically upgraded to UEK R7.

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's supported. Downgrading kernel packages is unsupported, 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 added 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 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 the application vendor.

The kernel ABI for a UEK release remains unchanged in all later 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's independent of the kernel version that underlies the OS. 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 installations on premises.

  • Boot ISO of Oracle Linux for network installations

  • Boot ISO of the official UEK release for installing on hardware which 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 ISO images for the three most recent updates to the Oracle Linux releases, see https://yum.oracle.com/oracle-linux-isos.html.

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

Note:

Aside from installation ISO images, 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're 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 and information about any known issues that might arise when upgrading the system, see Oracle Linux 8: Upgrading Systems 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 provides direct memory access between two systems that are connected by a network. RDMA improves 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 the system is subscribed to the appropriate channels on ULN or that you have enabled the appropriate repositories on the Oracle Linux yum server.

For more information about RDMA, including any known issues, see Unbreakable Enterprise Kernel documentation for the required kernel.

RDMA With UEK R6

If you're 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 the system is newly registered on ULN, then the system 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 before installing RDMA packages.

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

  • ol8_UEKR6

  • ol8_baseos_latest

  • ol8_appstream

  • ol8_UEKR6_RDMA

Note that if the 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 before installing RDMA packages.

RDMA With UEK R7

If you're 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 the system is newly registered on ULN, then the system is already subscribed to the ol8_x86_64_UEKR6, ol8_x86_64_baseos_latest, and ol8_x86_64_appstream channels by default. Disable ol8_x86_64_UEKR6 and then explicitly subscribe to the ol8_x86_64_UEKR7_RDMA and ol8_x86_64_UEKR7_RDMA channels before installing RDMA packages.

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

  • ol8_UEKR7

  • ol8_baseos_latest

  • ol8_appstream

  • ol8_UEKR7_RDMA

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