What is paging to a filesystem?
Hopefully, you already understand paging to paging space (also called virtual memory). AIX (and other UNIX versions) page in the read-only code from a program as you start it and as it runs. This is just like paging in from the paging space but is directly from the filesystem, this is also true for shared libraries (which you might not be aware you are using). Also programs using memory mapped files access the files by simply reading and writing memory addresses – AIX will page in the file pages as necessary and they will get paged back to the filesystem to free up memory or if the program forces it.
