Linux Kernel#

uname

Common kernel packages:

[root@rhel9-a ~]# dnf list available kernel kernel-{core,devel,headers,modules,modules-extra,tools,tools-libs}
Updating Subscription Management repositories.
Last metadata expiration check: 1:56:28 ago on Mon 28 Jul 2025 07:19:57 PM UTC.
Available Packages
kernel.x86_64                      5.14.0-570.30.1.el9_6        rhel-9-for-x86_64-baseos-rpms   
kernel-core.x86_64                 5.14.0-570.30.1.el9_6        rhel-9-for-x86_64-baseos-rpms   
kernel-devel.x86_64                5.14.0-570.30.1.el9_6        rhel-9-for-x86_64-appstream-rpms
kernel-headers.x86_64              5.14.0-570.30.1.el9_6        rhel-9-for-x86_64-appstream-rpms
kernel-modules.x86_64              5.14.0-570.30.1.el9_6        rhel-9-for-x86_64-baseos-rpms   
kernel-modules-extra.x86_64        5.14.0-570.30.1.el9_6        rhel-9-for-x86_64-baseos-rpms   
kernel-tools.x86_64                5.14.0-570.30.1.el9_6        rhel-9-for-x86_64-baseos-rpms   
kernel-tools-libs.x86_64           5.14.0-570.30.1.el9_6        rhel-9-for-x86_64-baseos-rpms

dnf info <package> for more details.

Show current kernel version:

[root@rhel9-a ~]# uname -r
5.14.0-570.25.1.el9_6.x86_64

Can also check kernel version info by viewing /proc/version and /proc/cmdline info files:

[root@rhel9-a ~]# cat /proc/version
Linux version 5.14.0-570.25.1.el9_6.x86_64 (mockbuild@x86-64-05.build.eng.rdu2.redhat.com) (gcc (GCC) 11.5.0 20240719 (Red Hat 11.5.0-5), GNU ld version 2.35.2-63.el9) #1 SMP PREEMPT_DYNAMIC Sat Jun 28 13:03:53 EDT 2025

[root@rhel9-a ~]# cat /proc/cmdline
BOOT_IMAGE=(hd0,msdos1)/vmlinuz-5.14.0-570.25.1.el9_6.x86_64 root=/dev/mapper/rhel_rhel9-root ro biosdevname=0 no_timer_check vga=792 nomodeset text resume=/dev/mapper/rhel_rhel9-swap rd.lvm.lv=rhel_rhel9/root rd.lvm.lv=rhel_rhel9/swap net.ifnames=0 crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M

Kernel directory structure#

Notable filesystems:

/boot
/proc
/usr/lib/modules

Notable /proc files:

/proc/cpuinfo
/proc/meminfo
/proc/version
/proc/cmdline