The System Paging Activity workspace provides information about factors that affect system paging rates. Because the process of paging is very slow when compared to referencing data from real or expanded storage, it is important that page dataset devices be isolated from contention with other kinds of work. This is especially true if there is contention for real and expanded storage, and the page fault rate is high.
Bar charts on this workspace graphically illustrate the factors enumerated in the table view. In the Page Rates bar chart, a high page fault rate (the number of page-ins per second) may indicate contention for storage. A high system page rate may indicate high paging activity over one or more of the storage areas (common, system, or private) resulting in storage contention.
A high number of expanded storage pages moved may indicate that expanded storage is being depleted. This may cause increased z/OS overhead.
The unreferenced interval count is inversely related to contention for real storage. The lower the unreferenced interval count, the more quickly frames are being referenced. In some cases, a low count is not necessarily indicative of a paging problem. To determine whether real storage is being overused, use this factor in conjunction with the page fault rate.
The auxiliary storage manager (ASM) is the z/OS component responsible for managing page dataset I/O. A large ASM queue can negatively impact system performance.
This workspace can record history.
See also:
Organization
of system-level predefined workspaces
Attribute groups used by system-level predefined workspaces