1. To check current kernel version on CentOS, open a command-line interface and enter following command:

    # uname -msr

  2. To update CentOS software repositories, use the command:

    # sudo yum -y update

  3. To install the new kernel version, a new repository (ELRepo repository) needs to be enabled, type:

    # sudo rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org

  4. Next, install the ELRepo repository by executing the following command:

    # sudo rpm -Uvh https://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm

  5. Allow the system to finish performing the operation.

  6. To list available kernels, enter:

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

  7. To install the latest mainline kernel:

    # sudo yum --enablerepo=elrepo-kernel install kernel-ml

  8. Reboot your system by running the command:

    # reboot

  9. In case VM is not accessible after this step then soft reboot from Fiware-Lab GUI.

  10. To set Default Kernel Version type the following in the terminal:

    # sudo vim /etc/default/grub

  11. Once the file opens, look for the line that says GRUB_DEFAULT=X, and change it to GRUB_DEFAULT=0

  12. Save the file, and then type the following command in the terminal to recreate the kernel configuration:

    # sudo grub2-mkconfig -o /boot/grub2/grub.cfg

  13. Reboot once more:

    # reboot

  14. In case VM is not accessible after this step then soft reboot from Fiware-Lab GUI.