ZPAGEOPT parameter

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1 mb page areas


Default value
Parameter type
Where set
On User 0's parameter line.
Related products
Model 204 V7.4


ZPAGEOPT is a User 0 parameter applicable to z/OS systems only.

ZPAGEOPT specifies the areas that should be allocated using 1MB pages.

The following settings are valid:

Note: Any non-zero setting of ZPAGEOPT fails if the containing load library is not APF authorized.

X'0001'Use 1MB pages for servers above the bar.

Any server areas allocated above the bar (swappable (SERVGA) or non-swappable (SERVNSA)) will be allocated using 1MB pages. This improves LTB (look-aside translation buffer) hits by reducing the number and size of segment and page translation tables, resulting in a performance improvement for the Online.

X'0002'Use 1MB pages for buffers above the bar.
X'0004'Use 1MB pages for buffer hash cells above the bar.
X'0008'Use 1MB pages for buffer control blocks above the bar.
X'0010'Use 1MB pages for CCATEMP pages in storage above the bar.
X'0020'Use 1MB pages for CCATEMP in storage control blocks.
X'0040'Use 1MB pages for the record locking table when it resides above the bar.
X'0080'Use 1MB pages for CCAAPSY (APSY saved compilations in storage above the bar). From V7.6 onwards, this allocation will not include Resident Requests (RESREQST).