As we have seen, the HP-UX swap reservation policy in combination with the kernel-tunable swapmemon feature allows the administrator control of the paging dynamics of the system. Swap is a necessary evil in many cases; it should be configured in alignment with the available memory resources and the anticipated needs of the system's process loads.
There is another type of memory that we haven't discussed yet: secondary or non-core memory. We are referring to our old friend, rotating magnetic disk memory. Disks provide nonvolatile memory for short-term and long-term storage. The next stop on our tour of HP-UX internals is an in-depth look into the kernel file management subsystem.