@jemerson93 It’s very interesting we see this or similar issues on many different platforms - hardware as well as virtualized environments. There does not seem to be a general answer and those kind of things have been around for years - when you search for
rcu_sched you find tons of messages in kernel related mailing lists and forums.
But still this got more and more lately in the FOG forums as well and we are not sure why yet. But moving back to 4.15.2 kernel helped most of the people. We have seen issues with the newer init files not being compatible with this kernel and so I might ask you to manually download those more compatible inits (64 bit and 32bit). Rename/backup the ones you have in
/var/www/html/fog/service/ipxe and put those in place (names
init_32.xz). Then downgrade to the 4.15.2 kernel and see if you still get the ugly error you had before when trying to downgrade the kernel.
If that doesn’t work then I expect this particular issue to be a problem with Hyper-V and Linux kernel option PAGE_TABLE_ISOLATION - Meltdown patch (ref). But would be kind of strange as we have this option enabled in all later kernel version. Nevertheless you can try going back to even older versions of kernel and init. Find those used in FOG 1.5.0 here (kernel 4.13.4).
Beside that I have tried to find current information specific to Hyper-V. Not much I could find, really. https://access.redhat.com/solutions/3743631 (anyone who’s access to RedHat stuff? @Wayne-Workman?)