I’ve seen this issue on about 15 different servers now. Anybody else seeing this?
I also have a video of the boot process if that will be helpful.
Are you missing the initrd line in /boot/grub/menu.lst? That’s a known bug that I believe has been fixed with 3.18.25-something.
“Can’t find rootfs” is most likely the missing initrd bug, which is fixed in CentOS-release-xen-7-12 or later.
1. Manually add the initrd line to the xen stanza in /boot/grub/menu.lst, or
2. Upgrade to CentOS-release-xen-7-12 or later, and then
2a. Run grub-bootxen.sh manually, or
2b. Update the kernel (which will cause grub-bootxen.sh to be run automatically).