Reboot from hard disk error on a dedicated server

I've an issue with my dedicate server (OVH). After running rescue mode for general checks (all running correctly), I can't reboot in hard disk mode ( an error occurred). On hard disk mode, seems that server don't ping correctly. Support of OVH have solved the error changing the server in the rescue mode again.
On rescue mode server seems work correctly.
Obviously I need to reboot on hard disk mode, but rebooting don't work.
Can you help me with this error?
Thank you
Massimo
PS: of course is urgent because all my sites on the server are down currently.