Checking Available Kernels on the System

Kernels are named to include the upstream version number and the distribution build numbering. The kernel names on Oracle Linux also include indications of whether they're standard RHCK or whether they're UEK based. Also, the names identify their system architecture. For example, the el8 suffix indicates an RHCK, while el8uek indicates a UEK. See About Linux Kernels for more information.

Several methods are available for checking which kernels are available on a system:

List the kernels in the /boot directory.
```
ls -l /boot/vmlinuz*
```
The command produces an exact list of kernels available on the system. However, because of the way kernels are named, the kernel version that the system uses isn't easily identifiable.
Use the grubby command on specific kernels or using the ALL option.
```
sudo grubby --info /boot/vmlinuz-5.15.0*
sudo grubby --info ALL
```
The command provides fuller information about the boot configuration associated with each kernel in the system's /boot directory. The details are based on the GRUB title configuration.