How to install kernel from rescue mode CentOS / RHEL 7?

Updated: 28 September 2026 · Applies to: AlmaLinux 9 / Rocky Linux 9

CentOS/RHEL 7 are end of life. If AlmaLinux 9 / Rocky Linux 9 cannot boot because the kernel is missing or damaged, install it again from the rescue environment.

Boot from the installation ISO

• Ucartz VPS: in the VPS dashboard (client area › your VPS service), add the AlmaLinux 9 / Rocky Linux 9 ISO in the ISO section, set the boot order to CD Drive first, then Stop and Start the VPS and open VNC. If ISO support is not available for your VPS, ask our support team.
• Dedicated server: attach the ISO with the server's remote console, or ask our support team.

Start the rescue environment

1. In the ISO boot menu choose Troubleshooting, then Rescue a … system.
2. Choose 1) Continue so the rescue environment mounts your installed system read-write under /mnt/sysroot.
3. Press Enter for a shell, then run chroot /mnt/sysroot to work inside your installed system.

When you are done, type exit twice, remove the ISO, set the boot order back to Hard Disk and restart.

Reinstall the kernel

Inside chroot /mnt/sysroot, with a working network connection:

dnf reinstall kernel-core kernel-modules kernel      # or: dnf install kernel if none is left
grubby --info=ALL | grep ^kernel                     # check the boot entries
grubby --set-default /boot/vmlinuz-<version>

Without a network connection, install the packages from the ISO instead. Leave the chroot (exit), mount the ISO and look at the kernel package names:

mkdir -p /mnt/iso && mount /dev/sr0 /mnt/iso
cd /mnt/iso/BaseOS/Packages
ls kernel-*.rpm

Install kernel, kernel-core, kernel-modules and (on 9.1 and later) kernel-modules-core into the installed system:

rpm -ivh --root=/mnt/sysroot --force kernel-5.14*.rpm kernel-core-5.14*.rpm kernel-modules-5.14*.rpm kernel-modules-core-5.14*.rpm

Note: The kernel from the ISO may be older than the one you had. Run dnf upgrade after the system boots again.