(...)
Please post a follow-up, I'm curious what went wrong. :)
Maybe your server is hanging at fsck recovery shell waiting for root password (or user interaction).
Probably that.
Do you have a option to reboot you system into rescue mode or better a KVM over IP ?
Sorry, no, that server was not bought with rmm3 from intel, so we don't have a kvm for it. I'll repost on monday to let you know what it was.