Upgrade Kernel of CentOS 7 (RHEL 7)

upgrade-kernal-el7.md

Upgrade Kernel of CentOS 7 (RHEL 7)

1. Install elrepo

   wget https://elrepo.org/linux/kernel/el7/x86_64/RPMS/elrepo-release-7.0-8.el7.elrepo.noarch.rpm
   sudo rpm -Uvh elrepo-release-7.0-8.el7.elrepo.noarch.rpm
   sudo vi -i 's|http://elrepo.org/linux|https://linux.cc.iitk.ac.in/mirror/centos|g' /etc/yum.repos.d/elrepo.repo

2. List available Kernels

   sudo yum list available --disablerepo='*' --enablerepo=elrepo-kernel

3. Install kernel-lt

   sudo yum --enablerepo=elrepo-kernel install kernel-lt
   #sudo yum remove kernel-headers kernel-tools kernel-tools-libs 
   #sudo yum --enablerepo=elrepo-kernel install kernel-lt kernel-lt-headers kernel-lt-tools kernel-lt-tools-libs

4. Install kernel-lt or kernel-ml

   • kernel-lt (long term support)

     sudo yum --enablerepo=elrepo-kernel install kernel-lt
     #sudo yum remove kernel-headers kernel-tools kernel-tools-libs 
     #sudo yum --enablerepo=elrepo-kernel install kernel-lt-headers kernel-lt-tools kernel-lt-tools-libs

   • kernel-ml (mainline stable)

     sudo yum --enablerepo=elrepo-kernel install kernel-ml
     #sudo yum remove kernel-headers kernel-tools kernel-tools-libs 
     #sudo yum --enablerepo=elrepo-kernel install kernel-ml-headers kernel-ml-tools kernel-ml-tools-libs

5. Check installed Kernels

   rpm -qa | grep kernel | sort

6. Active Kernel without reboot (If need)

   sudo kexec -u
   sudo kexec -l /boot/vmlinuz-5.4.278-1.el7.elrepo.x86_64 --initrd=/boot/initramfs-5.4.278-1.el7.elrepo.x86_64.img --reuse-cmdline
   sudo systemctl kexec