Reliability of a redundant computer system, taking into account the features of restoring information of various criticality to loss

A fault-tolerant redundant computer system is considered, including a duplicated computer node with two two-input storage devices connected to it. A Markov model of a duplicated computer system is proposed, taking into account the physical and subsequent information recovery of memory. Variants of the discipline of information recovery are considered. In the first case, it is assumed that the information being restored is not unique and can be loaded into physically restored memory from some external source. For the second option, information can be restored only based on replicas of information stored in the system. The loss of all replicas of unique data can lead to the inability to restore information and, as a result, to an unrecoverable failure of the computer system. The comparison of the effectiveness of the options was carried out according to the non-stationary readiness coefficient.