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Review the OS/390 MVS Initialization and Tuning Guide
Document Number SC28-1751-05 for more details.
Storage Map
The common area contains system control programs and control
blocks. The following storage areas are
located in the common area:
- Prefixed storage area (PSA).
- Common service area (CSA).
- Pageable link pack area (PLPA).
- Fixed link pack area (FLPA).
- Modified link pack area (MLPA).
- System queue area (SQA).
- Nucleus, which is fixed and nonswappable.
Each storage area in the common area (below 16 megabytes)
has a counterpart in the extended common area (above 16 megabytes) with the
exception of the PSA.
Each address space uses the same common area. Portions of
the common area are paged in and out as the demands of the system change and as
new user jobs (batch or time-shared) start and old ones terminate.
The private area contains:
- A local system queue area (LSQA).
- A scheduler work area (SWA).
- Subpools 229, 230, and 249 (the authorized user key
area).
- A 16K system region area.
- Either a V=V (virtual = virtual) or V=R (virtual = real)
private user region for running programs and storing data.
Except for the 16K system region area and V=R user regions,
each storage area in the private area below 16 megabytes has a counterpart in
the extended private area above 16 megabytes.
Each address space has its own unique private area
allocation. The private area (except LSQA) is pageable unless a user specifies
a V=R region. If assigned as V=R, the actual V=R region area (excluding SWA,
the 16K system region area, and subpools 229, 230, and 249) is fixed and non
swappable. |