Hi, I haven't had chance to personally check this out but apparently the latest CentOS 7 kernel package doesn't boot under Xen PV: https://bugs.centos.org/view.php?id=13763 This may be highly relevant to you because an update was just pushed out for the KPTI feature (to help mitigate Spectre/Meltdown etc in Linux). As mentioned in that bug report, there are patches to fix this but they haven't yet been applied to the main CentOS kernel package. In the mean time you can use the kernel package from the CentOSPlus repository which does have this fix and the KPTI one. https://wiki.centos.org/AdditionalResources/Repositories/CentOSPlus All of this was researched by a customer having the problem today and it resolved it for them. Cheers, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting