Virtualisation. Remus. Remus provides transparent, comprehensive high availability to ordinary virtual machines running on the Xen virtual machine monitor. It does this by maintaining a completely up-to-date copy of a running VM on a backup server, which automatically activates if the primary server fails. Key features: The backup VM is an exact copy of the primary VM. When failure happens, it continues running on the backup host as if failure had never occurred. The backup is completely up-to-date . Main Page - OpenVZ Wiki.