An OpenVMS instance that does not share resources is called an independent instance . An independent instance of OpenVMS does not participate in shared memory use. Neither the base operating system nor its applications access shared memory. APMP Concepts Architecturally, APMP is based on an SMP hardware architecture. Each subsystem has full access to all other subsystems.
Shared memory is at the center.
Figure 2-1 APMP Diagram APMP supports the ability to divide the pie into multiple slices, each of disparate size. Each slice, regardless of size, has access to all of shared memory. Furthermore, because software partitions the pie, you can vary the number and size of slices dynamically. In summary, each slice of the pie is a separate and complete instance of the operating system. Each instance can see all of shared memory, which is where the application data resides.