Chapter 39. The Linux kernel

• Files

• RPM header (package metadata)

  The rpm package manager uses this metadata to determine dependencies, where to install files, and other information.

• Source RPM (SRPM)

  An SRPM contains source code and a SPEC file, which describes how to build the source code into a binary RPM. Optionally, the patches to source code are included as well.

• Binary RPM

  A binary RPM contains the binaries built from the sources and patches.

• kernel-core - contains the binary image of the kernel, all initramfs-related objects to bootstrap the system, and a minimal number of kernel modules to ensure core functionality. This sub-package alone could be used in virtualized and cloud environments to provide a Red Hat Enterprise Linux 8 kernel with a quick boot time and a small disk size footprint.
• kernel-modules - contains the remaining kernel modules that are not present in kernel-core.

• kernel-modules-extra - contains kernel modules for rare hardware and modules which loading is disabled by default.
• kernel-debug — contains a kernel with numerous debugging options enabled for kernel diagnosis, at the expense of reduced performance.
• kernel-tools — contains tools for manipulating the Linux kernel and supporting documentation.
• kernel-devel — contains the kernel headers and makefiles sufficient to build modules against the kernel package.
• kernel-abi-stablelists — contains information pertaining to the RHEL kernel ABI, including a list of kernel symbols that are needed by external Linux kernel modules and a yum plug-in to aid enforcement.
• kernel-headers — includes the C header files that specify the interface between the Linux kernel and user-space libraries and programs. The header files define structures and constants that are needed for building most standard programs.

Prerequisites

• Obtained kernel, kernel-core, kernel-modules, kernel-modules-extra RPM packages for your CPU architecture

Procedure

• List modules for kernel:

  $ rpm -qlp <kernel_rpm>
  (contains no files)
  …​

• List modules for kernel-core:

  $ rpm -qlp <kernel-core_rpm>
  …​
  /lib/modules/4.18.0-80.el8.x86_64/kernel/fs/udf/udf.ko.xz
  /lib/modules/4.18.0-80.el8.x86_64/kernel/fs/xfs
  /lib/modules/4.18.0-80.el8.x86_64/kernel/fs/xfs/xfs.ko.xz
  /lib/modules/4.18.0-80.el8.x86_64/kernel/kernel
  /lib/modules/4.18.0-80.el8.x86_64/kernel/kernel/trace
  /lib/modules/4.18.0-80.el8.x86_64/kernel/kernel/trace/ring_buffer_benchmark.ko.xz
  /lib/modules/4.18.0-80.el8.x86_64/kernel/lib
  /lib/modules/4.18.0-80.el8.x86_64/kernel/lib/cordic.ko.xz
  …​

• List modules for kernel-modules:

  $ rpm -qlp <kernel-modules_rpm>
  …​
  /lib/modules/4.18.0-80.el8.x86_64/kernel/drivers/infiniband/hw/mlx4/mlx4_ib.ko.xz
  /lib/modules/4.18.0-80.el8.x86_64/kernel/drivers/infiniband/hw/mlx5/mlx5_ib.ko.xz
  /lib/modules/4.18.0-80.el8.x86_64/kernel/drivers/infiniband/hw/qedr/qedr.ko.xz
  /lib/modules/4.18.0-80.el8.x86_64/kernel/drivers/infiniband/hw/usnic/usnic_verbs.ko.xz
  /lib/modules/4.18.0-80.el8.x86_64/kernel/drivers/infiniband/hw/vmw_pvrdma/vmw_pvrdma.ko.xz
  …​

• List modules for kernel-modules-extra:

  $ rpm -qlp <kernel-modules-extra_rpm>
  …​
  /lib/modules/4.18.0-80.el8.x86_64/extra/net/sched/sch_cbq.ko.xz
  /lib/modules/4.18.0-80.el8.x86_64/extra/net/sched/sch_choke.ko.xz
  /lib/modules/4.18.0-80.el8.x86_64/extra/net/sched/sch_drr.ko.xz
  /lib/modules/4.18.0-80.el8.x86_64/extra/net/sched/sch_dsmark.ko.xz
  /lib/modules/4.18.0-80.el8.x86_64/extra/net/sched/sch_gred.ko.xz
  …​

Procedure

• To install a specific kernel version, enter the following command:

  # yum install kernel-{version}