Chapter 2 Shipped Kernels

Oracle Linux 7 Update 5 ships with the following kernel packages:


Red Hat Compatible Kernel (RHCK).


Unbreakable Enterprise Kernel Release 5 (UEK R5), which is the default 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 minimum kernel version supported is the one included in the image. Downgrading kernel packages is not supported, unless recommended by Oracle Support.

The kernel source code for the shipped kernel is available after the initial release through a public git source code repository at


Any system that is installed using any Oracle Linux 7 ISO that is subsequently registered with the Unbreakable Linux Network (ULN), is automatically subscribed to the ol7_x86_64_latest and ol7_x86_64_UEKR5 channels and are configured to download the latest Unbreakable Enterprise Kernel Release 5 (UEK R5) release on the next system update. When you run yum update just after registering with ULN, the system is upgraded to the Oracle Linux 7 Update 6 release and the default kernel is automatically changed to UEK R5. If you prefer to continue to use and alternate kernel, such as UEK R4, you must manually change the subscriptions for the system in ULN before you perform the system update.

Systems that are not registered with ULN retain any existing yum channel configuration and continue to use the kernel installed with Oracle Linux 7 Update 5. If you are not registered with ULN and wish to upgrade to also use UEK R5, you must enable the ol7_UEKR5 repository in your yum configuration.