A method for error detection during execution of a real-time operating system, wherein logically-identical instances of the real-time operating system are executed in parallel on a plurality of processor cores of a first processor in a shared virtualization environment. The hypervisor supervises the parallel execution of the instances, and during execution of a hardware access initiated by the instances, the data transmitted during the hardware access for each instance of the logically-identical instances is compared with each other by the hypervisor. In the event of a discrepancy between the transmitted data or in the event of a unilateral hardware access initiated by one of the instances, an error is deemed to be detected by the hypervisor.