CentOS 7 -Distro Kernel - KVM Migration- Not Booting

Hello All,

I've been searching the forum and google but not getting any further.

I just tried migrating one of my CentOS 7 linodes from XEN to KVM.

I had installed the distro based kernel and was using grub-pv because I needed to install a complied module.

My Linode Configuration Profile is set to use Grub (legacy) and "Distro Helper" is enabled.

When I try to boot the machine the console shows
> Booting "`CentOS (3.10.0-229.1.2.el7.x86_64)' "

And nothing more. Just a black screen and it never comes back.

I've booted using the finnix recovery successfully and checked that /boot/grub/menu.lst has the modified the path to root as /dev/sda as expected.

looks like Grub2 is not installed on this server. I've read that there may be some other options in regards setting to the console=ttyS0 but so far no luck trying that either. Grub throws an error saying that the "variable prefix is not set" and just sits there. No recovery console or anything.

Can anyone advise?

> [root@server5 scripts]# cat /boot/grub/menu.lst

timeout 5

title CentOS (3.10.0-229.1.2.el7.x86_64)

root (hd0)

kernel /boot/vmlinuz-3.10.0-229.1.2.el7.x86_64 root=/dev/sda

initrd /boot/initramfs-3.10.0-229.1.2.el7.x86_64.img

1 Reply

It looks like none of the virtio modules were included in my initrd since the kernel was installed on a xen system.

As per: http://wiki.libvirt.org/page/Virtio I tried rebuilding the initrd to include the virtio modules but got tired of monkeying with it and decided to go the following route.

Now having it working to see which modules are loaded, I realize that I was missing virtio scsi support and probably others.

I simply booted using Linode kernel. Completely removed all traces of the previous kernel install. Installed the latest distro kernel and packages, installed and configured grub2. Then installed my custom modules again.

Seems to have worked.

However not I notice that the grub menu does not work/display.

This is also reported by others in the forum with no real defined fix that I can see.

https://forum.linode.com/viewtopic.php?f=20&t=12000

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