Page data set volume 1
The recommended types of data sets for this volume are:
- PLPA (1-cylinder allocation)
- Common
Unless your system is central-storage constrained, and has significant PLPA paging activity, there is little or no performance impact to combining the PLPA and COMMON page data sets. The PLPA data set should be allocated first, as a 1-cylinder data set. The COMMON data set should be allocated second, immediately following the PLPA data set on the volume. The COMMON data set's size should be large to contain both PLPA and COMMON pages.
This causes the vast majority of PLPA pages to be written to the COMMON page data set during IPL. This allows the operating system to use chained CCWs within a single data set and improves performance when both data sets are on the same volume.
Note: A warning message (ILR005E) is issued during IPL when
PLPA pages overflow into the COMMON page data set during CLPA processing.
This message is intended to alert you to the possibility that PLPA
pages might have to be retrieved from data sets on different volumes
(which would negatively affect performance if there was significant
PLPA paging). When PLPA and COMMON page data sets are on the same
volume, this message can be ignored.