1. We're going to use the mainline kernels precompiled and made available by ELRepo. Firstly, we need to enable their repo on the CentOS box.
2. Then, we're going to actually install the kernel using yum - very simple.
3. Finally, we'll edit grub.conf to ensure the server reboots to the latest kernel, and then we'll be good to go.
4. Before you start, please make sure you have console or VNC access to your server in case you need to boot back to an older kernel version!
CentOS 7
Run the following commands via SSH:
rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.orgNow we need to set grub_default to 0 in the configuration, to automatically boot to the newest kernel:
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm
yum --enablerepo=elrepo-kernel install kernel-ml -y
nano /etc/default/grub
Finally, we set the default kernel, rebuild grub with the latest configuration and then reboot the server.GRUB_TIMEOUT=5
GRUB_DEFAULT=0
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL_OUTPUT="console"
GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet"
GRUB_DISABLE_RECOVERY="true"
grub2-set-default 0
grub2-mkconfig -o /boot/grub2/grub.cfg
reboot
If the server does not reboot, check the console/VNC and correct any errors, or reboot to an older kernel and contact your IT admin.
If the server reboots, but using the wrong kernel (check with uname -a) then you might need to populate the /etc/default/grub file with defaults, and rebuild grub2 config with "grub2-mkconfig -o /boot/grub2/grub.cfg". Please check this page for more information: https://wiki.centos.org/HowTos/Grub2
CentOS 6
Run the following commands via SSH:
rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
rpm -Uvh http://www.elrepo.org/elrepo-release-6-8.el6.elrepo.noarch.rpm
yum --enablerepo=elrepo-kernel install kernel-ml
Now we need to edit /etc/grub.conf and change "default=1" to "default=0" to automatically boot to the latest kernel. Once done, issue the reboot command and check the kernel version (uname -a) once the server comes back.
If the server does not reboot, check the console/VNC and correct any errors, or reboot to an older kernel and contact your IT admin.
Source: http://elrepo.org/tiki/kernel-ml
