[CentOS] Cannot boot CentOS 7 VM after updating Host CentOS 7 Kernel

Sun Oct 30 23:31:54 UTC 2016
Paul R. Ganci <ganci at nurdog.com>

On 10/30/2016 03:05 PM, Eero Volotinen wrote:
> so, Just chroot to mountpoint:
>
> http://www.cyberciti.biz/faq/unix-linux-chroot-command-examples-usage-syntax/
>
> chroot /mounted/path /bin/bash and then .. mkinitrd (see man page for 
> documentation)
Thank you for the hint. The way I fixed this problem was to do this:

1.) Booted into linux rescue mode using the CentOS-7-x86_64-DVD-1511.iso
2.) chroot /mnt/sysimage
3.) Used nmtui to setup a network
4.) yum update (installed the 3.10.0-327-36.3.el7.x86_64 kernel)
5.) grub2-mkconfig -o /boot/grub2/grub.cfg 6.) yum reinstall 
kernel*-3.10.0-327-36.3.el7.x86_64

Step 5 was necessary because of a grubby error indicating that there was 
no suitable template. Step 6 was necessary because according to the 
googled page I found regarding step 5 indicated that the default kernel 
would not be that found in step 4. I probably could have skipped step 4 
and just done steps 5 and 6. But the VM is now up and running the latest 
kernel.

Now the question is how did this happen. My best guess is that the VM 
was unhappy when I booted the host while it was running. Is rebooting 
the host without shutting down guests first a risky thing to do?
-- 
Paul (ganci at nurdog.com)
Cell: (303)257-5208