[CentOS] CentOS 7 cloned VM cannot boot

On 6/5/2017 12:09 μμ, Nikolaos Milas wrote:

> The VM booted fine after /etc/fstab update! 

I did another test, which was also successful.

Below follows the output from the process (after booting in 
troubleshooting mode using the CentOS 7 media disk):

    1) Continue

    2) Read-only mount

    3) Skip to shell

    4) Quit (Reboot)

    Please make a selection from the above: 1
    =======================================================
    =======================================================
    Rescue Mount

    Your system has been mounted under /mmt/sysimage.

    If you would like to make your system the root environment, run the
    command:

             chroot /mnt/sysimage
    Please press <return> to get a shell.
    When finished, please exit from the shell and your system will reboot.
    sh-4.2# umount /dev/vda1
    sh-4.2# xfs_admin -U restore /dev/vda1
    Clearing log and setting UUID
    writing all SBs
    new UUID = b05227b2-7c86-4ccf-81ff-204a9a80f789
    sh-4.2# mount /dev/vda1 /mmt/sysimage/boot
    sh-4.2# chroot /mnt/sysimage
    bash-4.2# grub2-install /dev/vda
    Installing for i386-pc platform.
    Installation finished. No error reported.
    bash-4.2# nano /etc/fstab
    bash-4.2# exit
    sh-4.2#

Note also that after logging into the (finally bootable) OS, we should 
follow the directions: "Resetting and Reinstalling GRUB 2".

https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/System_Administrators_Guide/sec-Reinstalling_GRUB_2.html#sec-Resetting_and_Reinstalling_GRUB_2

Best regards,
Nick