Logical partitions (LPARs) are, in practice, equivalent to separate mainframes. Each LPAR runs its own operating system. This can be any mainframe operating system. The system administrator can assign one or more system processors for the exclusive use of an LPAR. The operating system in each LPAR is IPLed separately, has its own copy of its operating system, has its own operator console (if needed), and so forth. If the system in one LPAR crashes, there is no effect on the other LPARs.